Geography Reference
In-Depth Information
the decennial censuses from 1940 to 2010, some nineteen of these from
1930, some ten from 1920, and some limited information back to 1910
for eight of these cities.
4
Using new materials recently developed from
both the NHGIS and data from the 1880 census, it is now possible to see
emerging paterns well before the Great Migration began.
5
This essay makes use of these data to begin to look at the actual
patern of residential segregation of African Americans in the United
States. Using these materials, it is possible to begin to address the pat-
terns of change in a more rigorous manner. Maps will be used to visualize
paterns of segregation and how it changed in Chicago, the city that for
many reasons is the most used to typify the urban United States. Using
conventional measures of segregation, this analysis will examine how
typical the paterns found in Chicago were compared to those found in
cities in the rest of the United States.
Making this project possible was the development of census tracts
in the United States, a process that began in 1910, and compilation of the
early census tract data from a variety of cities for the early twentieth cen-
tury. Census tracts make it possible to report data from relatively small
areas; these areas were developed by the Census Bureau in consultation
with local officials. Currently, each tract averages roughly four thousand
in population. Until 1990 the tracts were delineated with hand-drawn
maps. It was only the advent of NHGIS that made it possible to actually
map urban areas using tracts over time. Tracts were expressly designed
to report on small areas in urban setings and thus provide more de-
tail for highly populated places. Indeed, the Census Bureau introduced
tracts for the purpose of making New York City more comprehensible.
The census tract movement began in New York in 1906 when urban
planner Walter Laidlaw suggested that the city be divided into units ac-
cording to population for the 1910 census. For the most populous neigh-
borhoods, such as most of Manhatan and portions of Brooklyn and the
Bronx, a measure of approximately forty acres was used, with each tract
averaging about eight city blocks. The rest of the city was divided into
larger areas. Laidlaw also convinced the Census Bureau to create and
draw census tracts and to tabulate data for other cities that had more
than 500,000 inhabitants in 1910. These cities included Boston, Philadel-
phia, Baltimore, Pitsburgh, Cleveland, Chicago, and St. Louis. Tract-
