The United States Census Bureau
http://www.census.gov/
US State & County Census Quickfacts
http://quickfacts.census.gov/qfd/
Quick, easy access to facts about people, business, and geography.
Bureau of Labor Statistics
http://stats.bls.gov/
Broad range of information in economy and labor statistics, including
Consumer Price Index, wages, and Occupational Outlook Handbook.
Historical
Census Browser
http://fisher.lib.virginia.edu/collections/stats/histcensus/
The data presented here describe the population and economy of
U.S. states and counties from 1790 to 1960.
Statistical
Abstract of the United States
http://www.census.gov/statab/www/
Online version of the handy reference book.
City
and County Databook
http://www.census.gov/statab/www/ccdb.html
Convenient resources for statistics of all U.S. counties and over
city or places with over 25, 000 inhabitants.
FedStats
http://www.fedstats.gov/
The gateway to statistics from over 100 U.S. Federal agencies.
CIA
World Factbook
http://www.cia.gov/cia/publications/factbook/
United
Nations Global Statistics
http://unstats.un.org/unsd/