We are very fortunate to have one of the best State Data Centers in the Nation!
Look here for an EASY way to find preformatted reports for Missouri and Illinois (as well as the rest of the country),
with much more detail available as needed.&nb

Official Census Bureau site for Census information, American Community Survey, More.

'The Missouri Spatial Data Information Service provides GIS and census data about the
state of Missouri to the public by way of anonymous FTP and this World Wide Web site.'

This is the official website for Census data. The Census Bureau publishes a lot of other statistical data besides the Decennial Census, so you might want to look around their homepage.

Which is bigger, a 'tract' or a 'block group'? What's the difference between a
'household' and a 'family'? The Glossary provides definitions to these
and many other terms used by various Census products.

Historical Census Browser. The data presented here describe the population and
economy of U.S. states and counties from 1790 to 1960.

The Census Bureau has mounted many (but not all) of the tables from 1790-1990 Decennial Censuses. There are tables included for 'places', but not for tracts, blocks or block groups.

"The National Historical Geographic Information System (NHGIS) provides, free of
charge, aggregate census data and GIS-compatible boundary files for the United States
between 1790 and 2000."

A very easy-to-navigate source for all sorts of government statistical data (not just Census!)

All Things Census is a gathering place for postings about census methods, findings and resources. As the 2010 Census revs up its engine, this site will look at how the machinery is running. When the data come out, starting late this year, it will feature reports on what the numbers say and mean. The site is produced by the Pew Research Center, a nonpartisan "fact tank" that provides information on the issues, attitudes and trends shaping America and the world.