This website provides year-to-year compatible map series showing the evolution of racial geography in 63 major American cities (complete list of MSA is available here). Each series starts from the earliest year for which racial data (at the census tract level) is available for a given city (no later than 1950) and continues until 2010. The earliest series starts in 1910. Census classification of race/ethnicity has changed over the 1910-2010 period. Our goal is to use a single classification over this entire period, however, this proved to be impossible. Thus, we use two sets of the racial classification, one for years 1910-1970 that uses 3 racial categories (White, Blacks, Asians (including also American Indians)) and another for years 1980-2010 that uses 5 racial categories (Non-Hispanic Whites, Non-Hispanic Blacks, Non-Hispanic Asians (including also American Indians), Non-Hispanic Others, and Hispanic/Latino origin population).
To show how race composition change in US major cities we use a diversity/dominant type map, because it presents the most information in a single map. Comparing the maps between years, viewers have to keep in mind two main changes in the race categorizations:
- Hispanic origin population until 1970 was included in the White category and since 1980 constitute as a separate category;
- Data for 1940 distinguish only between White and Non-White population; we assign Non-White population to Black; in some cases it leads to depicting Asian population incorrectly (i.e, Chinatown in San Francisco in 1940 will be incorrectly depicted as Black dominated area).
Detailed information about this dataset is described in
A. Dmowska, T. F. Stepinski (2020) Mapping changes in racial composition in the United States 1910-2010 using US census tract historical data.
(paper submitted to Historical Methods: A Journal of Quantitative and Interdisciplinary History).
EXAMPLES OF YEAR-TO-YEAR COMPATIBLE MAPS FOR SELECTED CITIES
Click on the name of the city to open a PDF file with the series of diversity/dominant race types maps showing how the racial topography change over the years. Maps for the other cities can be downloaded below as a zip archive.
WHAT IS INCLUDED IN OUR RESOURCES?
- zip archives containing a set of ESRI shapefiles of census tracts with a numerical database detailing the racial statistics for each tract (a headcount of each racial subpopulation, a share of each racial subpopulation, and the label of diversity/dominant race type classification). The default spatial display is the map of diversity/dominant race types. Maps of other variables (i.e, percentage of a given race) can be easily obtained using the GIS software. Name of zip archive is for example "ct_chicago_il. zip". It contains name of MSA (i.e, Chicago) and the 2-letters state code (i.e, il).
- zip archive consists of the set of the maps, plots and summary tables in PDF and MS Excel format prepared for the metropolitan statistical area (MSA) and for the main county within MSA (for example, files for Chicago, IL MSA and Cook County, IL). Name of zip archive is for example "ct_chicago_il_pdf.zip". It contains name of MSA (i.e, Chicago) and the 2-letters state code (i.e, il).
Included are 4 types of files (files for MSA start with the prefix “msa_”; files for the county starts with the prefix “cnt_”:
- PDF files with a series of diversity/dominant race types maps showing how the racial topography change over the years (i.e, msa_chicago_oh.pdf; cnt_chicago_oh.pdf)
- PDF files showing the evolution of racial composition (percentage of people of a given race) in form of a barplot (the number in the bars indicates the percentage of total population of given race in given year).
- PDF files showing the distribution of census tracts of different types (percentage of census tracts in a given diversity/dominant type) in form of a barplot (the number in the bars indicates the percentage of census tracts in a given diversity/dominant type). (i.e, msa_chicago_il_perc_tract.pdf; cnt_chicago_il_perc_tract.pdf)
- MS Excel files with two sheets: perc_tract contains percentage of census tracts in a given diversity/dominant type for the available years; perc_race contains percentage of a given race for the available years. (i.e, msa_chicago_il.xls; cnt_chicago_il.xls)
DOWNLOADING HISTORICAL CENSUS TRACTS
- From the dropdown menu select the name of metropolitan area. Click on "Download" button to download a zip archive. Name of zip archive is for example "ct_chicago_il.zip" for downloading data in ESRI Shapefile format and ct_chicago_il_pdf.zip for downloading set of maps and plots in PDF file format. It contains name of MSA (i.e, Chicago) and the 2-letters state code (i.e, il).
- Unzip a downloaded zip archive.
- In case of downloading data (i.e, ct_chicago_il.zip), directory will contain a set of ESRI Shapefiles and the QGIS legend files with the color scheme for displaying racial diversity/dominant race classification. The name of each ESRI shapefile consists of the name of MSA and the year; for example chicago_il_1930.shp is the file with census tracts for Chicago in 1930.
- In case of downloading PDF files (i.e, ct_chicago_il_pdf.zip), directory will conatain a set of PDF and MS Excel files (see section What is included in our resources?)
Select the name of Metropolitan area from the dropdown menu below and click "Downolad" to download zip archive containing data in the ESRI Shapefile format
Select the name of Metropolitan area from the dropdown menu below and click "Downolad" to download zip archive containing the set of the maps, plots and summary tables in PDF and MS Excel format
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