(We've moved to: http://christinesleeter.org/census-data-show-housing-patterns/)
Many people, especially white people, assume families generally live wherever they choose and can afford, and have done so for generations. Using the U.S. Census, you can look into this assumption. You may discover patterns you hadn’t anticipated.
Take a census page that includes someone in your family tree. By scanning the page, you can find out things such as: Does the neighborhood appear to be racially segregated? Segregated by country of immigration? If not, do families of different backgrounds seem to cluster together? Did families live mainly in individual residences or rooming houses? Were there servants, and if so, of what background? How diverse were the families by social class (using property value, if known, as a gauge of social class standing)?
You can also use the census to identify how housing patterns shift over time. If you are using Ancestry.com, an easy way to do this is to select the U.S. Census for a given year (such as 1870), then narrow down to a specific county, township, or enumeration district. Near the bottom of the search page, select a race, then search. You should get the total number of members of that race during that census year in that location. Do the same for every racial group counted in that census. Then use the same process for the next two censuses.
Do you see any patterns? For example, when researching my family history, I wanted to know if Southeastern Tennessee, where a branch of my ancestors lived, changed in racial composition after the Civil War. Using this process, I saw that even though in rural areas African Americans lived next to whites, over time the area became whiter and whiter, prompting me to wonder why, and how my ancestors were affected.
As another example, I was researching immigrants in my family tree who came into the U.S. through New Orleans before the Civil War and settled in Mississippi. I figured they encountered slavery for the first time when they arrived, but I wanted to picture the context. So I used the search process described above. I found out that about two-thirds of the people in the area where they were living were enslaved African Americans. What a context to learn racism and racial privilege!
Identifying these patterns can raise useful questions. For example, it is commonly assumed that after the Civil War and the abolishment of slavery, race gradually became less and less significant in where people lived. If data in the census reveal the opposite (which it usually will do), what was happening and why? Questions like this will prompt you to investigate other sources. One source I recommend is Sundown Towns by James Loewen, which reports a detailed analysis of racism in housing patterns through U.S. history, and debunks the myth that white towns are white because people of color choose to live elsewhere.