American Fact Finder
The official portal for finding data collected by the U.S. Census Bureau. It includes:

• -the Census 
  • - demographic data
  • - collected once every ten years
• -the American Community Survey
  • - socioeconomic data
  • - collected annually

Help using American FactFinder:

• Video tutorial: how to gather data
• Video tutorial: how to download and manipulate data
• Map of census tracts in Chicago neighborhoods

Using American FactFinder requires that you download data for each census tract in your neighborhood, then compile it. Fortunately, others have already done much of this work:

• Chicago Health Atlas
• infant mortality, age distribution, leading reportable illnesses

• Demographic and Socioeconomic Characteristics, excerpted from A Profile of Health and Health Resources within Chicago's 77 Communities
• race distribution

• Selected Socioeconomic indicators in Chicago, 2007-2011
•   poverty level, unemployment rate, educational attainment

• Hard to Find Census Data from the Chicago Data Guy (citywide data)
•  educational attainment, poverty status (by age and race), household income by race 

Block groups - consist of several blocks; there are typically between three and five block groups to a tract.

Community - a geographic area as defined in the 1920's as one of the 77Chicago areas created so the census bureau and social scientists could track statistics consistently in defined areas over time.

Congressional districts - a (physical) division of a state which is entitled to elect one member to the United States House of Representatives to represent their interests.

Neighborhood - a geographic area where it's boundaries are reevaluated after each federal census and its boundaries may change over time.

Tract - a geographic region defined for the purpose of taking a census. Usually these coincide with the limits of cities, towns or other administrative areas and several tracts commonly exist within a county. They have changed a great deal over the years, in most cases by splitting.

Ward - one of the City of Chicago's 50 legislative districts (also called political districts). Each ward has one elected alderman. Together they form a Council, which, with the mayor, govern the city. Ward boundaries must be re-drawn after every federal census.

Metro Pulse Community Snapshots

Contains a set of Community Data Snapshots created in September 2013 to summarize demographics, housing, employment, transportation habits, retail sales, property values, and land use for all 77 Chicago Community Areas

As noted in each profile, the data comes from multiple sources, which include the U.S. Census Bureau, the Illinois Department of Employment Security, the Illinois Secretary of State, the Illinois Department of Revenue, and CMAP.

The sources listed below include some historical data for Chicago community areas, though they are not comprehensive: