The lines that shape our cities

The term “redlining” has been making headlines throughout the past decade and was even a topic of discussion in the 2020 election. Why is redlining an issue worth discussing in the 21st century? Why are some maps made in the 1930s such a big deal? To answer these questions, we need to understand the connection between the nation’s history, urbanization, and physical geography. Through this lens we can vividly see the legacy of redlining, evidenced by inequitable environmental stressors in our cities and neighborhoods.     

Let’s start with some historical context. After the Civil War in the mid-1860s, the United States experienced a number of major events relevant to this discussion. Slavery was abolished and the second Industrial Revolution ended. The United States saw a massive influx of immigrants. The first World War and the Great Depression came to pass. The Supreme Court heard its first arguments about racial segregation. In what’s now known as the Great Migration, millions of Black Americans fled the South. Use the interactive timeline below to learn more about the historical turning points that influenced the eventual assignment of neighborhood ratings.  

By the 1930s, more than half the U.S. population—which had been predominantly rural up to then—was now living in cities. Many Black Americans moved from the rural South to northern cities seeking jobs and relief from Jim Crow laws designed to control them and their labor. However, northern cities had their own Jim Crow laws, including restrictive covenants that were embedded in property deeds in many White neighborhoods, prohibiting owners from selling to anyone who wasn't White.

During The Great Depression, President Franklin Delano Roosevelt immediately started implementing social assistance programs at an unprecedented scale. One noteworthy result of his New Deal federal stimulus programs was the creation of a new agency: the Home Owners Loan Corporation (HOLC).

The HOLC gave over one million emergency refinancing loans to homeowners between 1933 and 1936, including to people of color and immigrants. But the HOLC also hired real estate assessors to create color-coded, residential security maps. These maps used a rating scale to assign grades to neighborhoods reflecting their "residential security"—the supposed relative riskiness of a neighborhood to mortgage lenders like banks.

HOLC-backed assessors were generally older White males who made assessments based on their perceptions. Racism, nativism, and class privilege are clear in the grades as they possessed a clear pattern. They recorded their descriptions and designations on forms that are now available to view  online . Green areas, given grade “A,” were believed to be inhabited by the upper classes, such as businessmen and wealthy White people. Blue areas, given grade “B” ratings, meant the assessor classified the area as having “good people” like white-collar families. Yellow areas, given grade “C,” were considered declining areas with working-class people. Finally, grade “D” meant significant levels of detrimental influences. Assessors referred to these areas as “hazardous;” they were home to mostly foreign-born people, lower-class Whites, and Black people. The grade "D" neighborhoods were identified by the red lines drawn around them—hence the origin of the term "redlining."  

Evidence suggests that these HOLC maps were used by banks for decades after the emergency funding program ceased. Lenders used the maps to determine which neighborhoods would be safest for financial investment, but these assumptions were based solely on neighborhood descriptions, not information about individual borrowers.

Historian Kenneth Jackson described in his book, Crabgrass Frontier, that the HOLC maps “undervalued neighborhoods that were dense, mixed, or aging,” and “applied [existing] notions of ethnic and racial worth to real-estate appraising on an unprecedented scale.” While the maps didn’t create racism, they quickly became a tool for upholding racist systems and policies.

The HOLC maps may have expedited the loan process for lenders by recording some objective information about neighborhoods, such as proximity to rail yards and industrial areas. However, many of the beliefs that government assessors applied when creating the maps were entirely subjective, explicitly racist, and created or codified adverse conditions that still affect cities today.  

Nearly a century later, redlined neighborhoods continue to be affected by decades of divestment, and they still experience segregation in many ways. Public housing projects were designed to keep Black Americans in specific neighborhoods, while literal barriers including the Interstate Highway System bulldozed and displaced redlined and Black neighborhoods and separated them from urban cores. These nefarious practices likely created and amplified challenges for communities of color, including lower education rates, higher crime rates, lower home prices, lower credit scores, and absent city services for residents. The social effects of redlining are clear, but what about the effects of these maps on the physical environment?  

Federal real estate appraisers and assessors completed forms with their neighborhood descriptions for the assessed cities. Environmental terms were heavily used by appraisers when determining neighborhood classes, so it begs the question: What are the environmental conditions of historically redlined neighborhoods today?

The  Digital Scholarship Lab  at the University of Richmond performed a text analysis on the keywords in these HOLC forms. Researchers conducted their analysis by transcribing primary source documents, like the one above, into a database. Using the transcribed text, they were able to make the connection between environmental terms and their relationship to favorable or less favorable grade designations. Thanks to new advances in high-resolution datasets, we can thoroughly examine the environmental legacy of redlining on neighborhoods. 

While many have written about the socio-economic effects of redlining, more recently researchers are using Geographic Information Systems (GIS) analysis to uncover relationships between redlined areas and environmental conditions such as tree coverage, temperature, infrastructure, and topography. This type of analysis can help identify correlations between historically redlined areas and environmental inequalities.

 A recently published study  shows that urban heat islands—the increase of land surface temperature due to urban design and land uses—are more intense in formerly redlined neighborhoods than in areas with other grades. It also indicates that these formerly redlined areas tend to have more impervious surfaces and fewer trees than their non-redlined neighbors.

To better understand these relationships, let’s explore four environmental factors and how they relate to redlining in the following cities:

• Urban heat islands in St. Louis, Missouri
• Tree canopy coverage in Montgomery, Alabama
• Impervious surfaces in Fort Wayne, Indiana
• Topography in Oakland, California 

Located on the western bank of the Mississippi River, St. Louis became a destination for many Black Americans who, during the early years of the Great Migration, were leaving the South in search of better economic conditions and opportunities in the North. 

Using satellite data, Esri cartographers analyzed temperatures across neighborhoods in the city. When comparing the average temperatures of the HOLC-designated neighborhoods, the analysis shows that the grade "A" neighborhoods had cooler averages than the neighborhoods with B, C, and D grades.

Heat islands are defined by relatively higher daytime and nighttime temperatures. They also have characteristically higher levels of air pollution, result in higher energy bills, and create uncomfortable living conditions that can lead to heat-related illness, chronic respiratory symptoms, and even pre-term birth. During summer months, St. Louis temperatures can reach well over 90° F with high humidity, which can lead to illness or even cause death.

If you compare the adjacent maps below, you can see how heat islands relate to the urban landscape and the historic HOLC zones. Pay particular attention to the locations of city parks and their relative temperatures. Alternatively, explore areas that are more industrial—namely those along the Mississippi river where temperatures are relatively warmer.

You may notice a few patterns emerge from the St. Louis heat analysis, like the warmer temperatures in the “D” areas that are on the river at the industrial port areas. Looking to the west of the “D” areas, the “A” neighborhoods are much cooler. This is somewhat atypical, since areas next to rivers tend to be cooler thanks to the shady tree canopy along them. We’ll explore tree coverage our next city.

After the Civil War, Montgomery became an important regional hub for cotton processing, as well as a commercial hub for commodities such as corn, soybeans, and lumber. The central location in the state, its location on a river, and the solid railway infrastructure made Montgomery a convenient location for industrial activity.    

In the 1950s, this industrial city became a focal point for the Civil Rights movement after Rosa Parks refused to give up her seat to a White man on a city bus in protest to the city's racial discrimination laws. With support from Civil Rights leaders, including Dr. Martin Luther King, Jr., the 13-month long bus boycott commenced. After several months of protest, in 1956 the policy of racial segregation on buses was ruled unconstitutional by the U.S. Supreme Court.

Recalling the text analysis mentioned above, we noted that assessors frequently used words like "trees" and "shade" to describe “A” and “B” grade neighborhoods. After noticing that pattern, it inspired our team to do a spatial analysis for the city of Montgomery, Alabama, exploring the relationship between present-day tree coverage and historically redlined areas.

In this video the streets help to show the forms and features of the landscape, where the predictable squares show that the land is mostly flat, and winding roads show that there may be hills in the region. Trees usually indicate that these areas are cooler and there is more space available for the neighborhood residents for exercise and recreation.

As you can see, in general, the HOLC areas rated as grade "A" are significantly darker green than the grade "D" areas, which appear as shades of gray. The shades of gray are likely areas of that have significant amounts of pavement, which leads us to our next investigation.

Most human settlements have historically been built on seashores or rivers, and Fort Wayne, Indiana is no exception. Strategically located at the confluence of the St. Joseph and St. Marys Rivers, the city supported strong manufacturing and industry throughout the early 1900s.

After the mid-1950s though, many city-dwellers—especially the White residents—headed to the suburbs, some with the assistance of GI Bill benefits.   

Fort Wayne was among the cities influenced by the City Beautiful movement, where urban planners made efforts to include areas for green spaces like parks as part of their city's plan. Being relatively flat and at the junction of two rivers, Fort Wayne is particularly vulnerable to floods, especially in spring. After years of recurrent flooding, which hobbled the city center, officials removed the parking lots and retail business from the flood zone and constructed Headwaters Park. A major goal of this park is to soak up floodwaters and to reduce flood damage.

Using data from 2016, the Esri team identified areas of Fort Wayne’s landscape that have been paved or covered in hard, impervious, surfaces. These are areas where the natural landscape has been reduced or largely eliminated. Features that make up impervious surfaces include rooftops, highways, industrial and manufacturing areas, and parking lots. In urban landscapes, the large areas of impervious surfaces create heat islands (like those discussed above) and are usually the hottest parts of cities in the summer.  

Because impervious surfaces are hard or covered with some type of pavement, fewer trees can grow here; there’s simply less space is available for them. Instead of soaking up and filtering rain and stormwater, large areas of impervious surfaces merely funnel the water to other locations, often exacerbating flooding and overwhelming aging sewer systems. To make matters worse, this urban stormwater runoff carries chemicals and pollution left behind by vehicles and other sources directly into lakes, streams, and rivers. This impacts local businesses that rely on recreation, fishing, and habitats.    

Instead of being a resource as it is in natural landscapes, stormwater in these areas becomes a nuisance with potentially deadly consequences. Places with a high percentage of impervious surfaces tend to have problems with local flooding and ponding in heavy rains. 

In the map above, you can see that the areas graded as "C" and "D" in 1940 had a notably higher percent of impervious surfaces in 2016 than those graded "A."

Here is the breakdown of percent of impervious surfaces in each neighborhood grade, according to our analysis:

• Grade "D": 42.5% impervious   
• Grade "C": 42.1% impervious 
• Grade "B": 38.0% impervious 
• Grade "A": 31.9% impervious

While impervious surfaces can lead to flooding in the relatively flat land in Indiana, the hillside city of Oakland, California experiences different environmental challenges related to redlining.

After the California Gold Rush that started in 1849, Oakland’s population grew rapidly with an influx of immigrants from as far away as China. Its location on the coast and in the Bay made Oakland an obvious pick for the western terminal for the Transcontinental Railroad. After the railway was completed, Oakland’s location then made it an ideal site to develop a shipping harbor. (Today, Oakland’s seaport is the fifth busiest in the United States.)    

Oakland’s port and rail hubs made it into an industrial and manufacturing hub. During WWII, Oakland grew rapidly as Black Americans from the South sought out jobs in this booming sector. Racial tensions locally and nationally came to a head in Oakland, where the Black Panther Party was founded in 1966. Urban renewal programs, rampant gentrification, and local opposition to new housing have continued to stoke these tensions. The resultant exacerbated inequality in the Bay is more apparent than ever.

The topography of the East Bay where Oakland sits starts as a flat plain near the water and the slope steadily increases to the east into the desirable grade "A" neighborhoods along the foothills and ridges of Oakland and Berkeley. Let's explore the relationship between topography and the HOLC classes.

It’s not a surprise that people want their homes to have good views. It’s also not surprising that when a lot of people want something, like an unimpeded view, the cost of the property increases. People who have more wealth live in the more expensive areas. Something that may not be as obvious, though, is that people who cannot afford those hillside views have higher rates of emergency room visits caused by asthma, congestive heart failure, and stroke. The more affluent inhabitants of the hill neighborhoods also have life expectancies that are 14 years greater than someone in West Oakland, which is a neighborhood that was redlined in the 1930s.

Some of the reasons for the health inequalities include the concentration of pollution from industry, diesel particulate matter from trucks on the highways, and emissions from ocean-going shipping vessels at the port interacting with the local climate that can hold polluted air closer to the ground (known as an “marine inversion layer”). Marine inversions happen when air cooled by the Pacific gets trapped under warmer and denser air from above. The weather in the region, combined with its physical geography, therefore traps pollutants at the bottom of the Oakland hills. Wealthier inhabitants in Oakland literally get a breath of fresher air.

Cities are constantly changing. They respond to the ebb and flow of people moving in and out of urban areas. They’re transformed by urban growth and decay, economic conditions, and infrastructure improvements that alter the landscape. While cities may do independent improvement projects, federal involvement within cities has continued since redlining began. This happens most often to raze "blighted or "slum" neighborhoods in both large and small cities.

On the surface, renewal projects may seem like a positive initiative. Historically, however, they have led to the destruction of thousands of homes and neighborhoods. Urban renewal in the 1960s was meant to rejuvenate cities, but instead led to the displacement of underrepresented communities across the country. The misguided approach to neighborhood improvement plans is perhaps best demonstrated in the example of the events that occurred in the neighborhood of West Oakland, California.

In the 1960s, a span of several blocks along one side of Seventh Street was leveled, making way for a mammoth 12-square-block U.S. Postal Service distribution facility. A surplus World War II Sherman tank was used to demolish the Victorian homes lining side streets. While supporters claimed the facility was a goldmine, bringing more than a thousand new jobs, the vast majority of those jobs were filled by transferees from other postal facilities. Only a small amount of the facility jobs went to West Oakland residents. In this video, a West Oakland man describes how his neighborhood was a thriving area and recalls his experience of having his neighborhood destroyed in the name of progress.

When considering plans to restructure a neighborhood through “urban renewal,” urban planners have two fundamental approaches:

• Revitalization—this method keeps residents in their homes and provides avenues for neighborhood improvement.  
• Redevelopment—this method is easier, and seemingly cheaper, in the short term. It utilizes bulldozers to raze deteriorated buildings and then rebuild the area, often under the guise of major public works projects such as improving the Interstate Highway system and public transportation. Redevelopment plans sometimes include building public housing; it lures homeowners with the promise of new, upgraded housing that in reality tends to end up being poorly constructed, farther from job centers and racially segregated. 

In West Oakland, the decision was made to redevelop, not revitalize. The resultant destruction of homes displaced of thousands of families in order to build a highway and a Bay Area Rapid Transit train line. West Oakland is now completely altered and isolated from the rest of Oakland.

While some urban renewal projects turn out well, a significant amount of these projects end up amplifying conditions that are already inequitable. Now that the historical connection between physical geography, environmental factors, and redlined neighborhoods is clear—how does this relate to race and discrimination today?

The people in redlined areas experience fewer opportunities to grow and change. Home ownership is one of the most effective ways to build wealth, but people in redlined neighborhoods have been denied opportunities that would help them build wealth. They’re typically offered interest rates higher than those in “C,” “B,” and “A,” neighborhoods, and experience greater challenges securing loans simply because their address is in a redlined neighborhood.

The ongoing effects of policies that prevented people of color from having opportunities to build wealth has not only resulted in economic disparities, it created situations where neighborhoods’ environments are also having dramatic impacts on their health and wellbeing. Historical urbanization patterns, the social history of the United States, and the environmental factors we’ve discussed above have come together as a kind of perfect storm. Through this analysis, it’s clear that the ongoing legacies of the HOLC redlined maps demand even greater scrutiny and discussion today. Because when people in your city have their basic human needs met, then a city functions better overall, and that makes for a higher standard of living and a better life for everyone.

As we look to the future of our neighborhoods and cities it is critical to know the history and know how city planning works. It is only through representation and improvement that we can equitably keep the culture of our neighborhoods without displacing them.

Learn more about the inequality of urban renewal through this content developed by the University of Richmond Digital Scholarship Lab.

You can make a difference in your community. By paying attention to your city's planning committee public meetings. Show up. Make your voice heard. And ensure that your community members have fair representation so that people who tend to be silenced have their voices heard. Human beings are all people and living in a fair and balanced society is the key for making your city great.

Keep reading and learning about redlining and the inequities in your community. Start a conversation with your friends and family about this topic.