Bureau of Economic Analysis (BEA)

Perhaps the most important data on the U.S. economy is found here: the National Income and Products Account (NIPA): GDP and its components, personal income, and corporate profits. There is both current and historical NIPA data -- quarterly from 1946, and annual from 1929. They also offer extensive international data (Balance of Payments, Exports and Imports, Investment Position, U.S. Direct Investment Abroad, and Foreign Direct Investment in the United States) from recent years in a variety of formats. Data can be retrieved for specific times and frequencies.

On the regional side, it offers Gross State Product (GSP), State Personal Income (some annual data from as far back as 1929, with more recent quarterly data), Local Area Personal and Per Capita Personal Income, and Employment and Income Projections. Finally, it offers gross product by Industry and Tangible Wealth. Users can easily retrieve selected portions of this data.

In terms of reports, it offers the BEA monthly journal, "Survey of Current Business," which frequently explains recent data, changes in survey methods, and the like. This journal is offered online, free of charge. Finally, it offers extensive documentation on the methodologies of the Bureau of Economic Analysis and guides to their data, as well as information about themselves.

http://www.bea.gov/