In his book Our Kids, sociologist Robert Putnam argues that access to the “American Dream” has been made more difficult for many US youth by a “Opportunity Gap” that has emerged between kids on either side of a growing economic/educational divide. This guide has been created for students taking Learning in Community, Ohio History, and other courses which are examining the idea of "Opportunity Gap" by looking at population characteristics and other census-related data.
To locate population numbers for a town or city, visit https://www.census.gov/prod/www/decennial.html and click on a year.
For 1980 data:
For 1990 data
For 2000 data
For more recent data, visit the Census Bureau's QuickFacts site.
The Internet Archive has digitized many of the 19th and 20th century county histories which contain descriptive information about various aspects of each county (and often, community and/or township) through time.
Visit the Internet Archive's search page, and set up your search like this:
"history of allen county" ohio
Substitute your county for Allen above. Other states may be available.
Example: History of Allen County, Ohio / 1885 edition
Wikipedia can also be a good source for population data, especially for smaller communities. Be sure to check that any population data you find at Wikipedia is footnoted, so that you know the source of the data.