Statistics can be a key component to prove a point or to understand a topic. Below are some resources that may be of interest to you.

Data-Planet Statistical Datasets
Provides access to statistical data produced by U.S. Federal agencies, States, private organizations, and major intergovernmental organizations. There are up to 2 billion charts, maps, views, rankings, time series and tables available for use in the Data-Planet repository. Data-Planet Statistical Datasets offers powerful capabilities to compare & contrast multiple data series, perform statistical calculations on the data, and customize output views.

Historical Statistics of the United States

ICPSR  Through the Department of Sociology, The University of Iowa maintains membership in the Inter-University Consortium for Political and Social Research (ICPSR), which is operated by the University of Michigan. This membership enables members of the University community to obtain a vast array of data for secondary data analysis regarding economic, education, health, international, legal, legislative, political, and other areas of social research."ProQuest

Statistical Insight  
Provides abstracts and indexes of statistical information from over 100,000 U.S. government publications from 1973, state and private sources from 1980, and approximately 2000 documents from international organizations from 1983. Incorporates ASI subject and keyword searching. Full text or web links provided for some citations. PDF texts of all documents indexed and abstracted in ASI from 2003 forward.

Statistical Abstract of the United States

There are many other data sources in addition to these.