The BEA is a unit of the Commerce Department. It tracks economic statistics
including the Gross Domestic Product.
The BLS is responsible for computing the Consumer Price Index, the
unemployment rate, and a host of other economic indicators.
They also publish the Statistical Abstract of the United States, an
important data source.
The AAPOR is the main professional organization in the polling field.
The Gallup Poll website contains an archive of their poll results, dating
back to the 1930's.
The Pew Research Center for People and the Press' site gives a wide variety
of poll results.
The Roper Center, located at the University of Connecticut, is another
outstanding archive of public opinion survey data.
The main scholarly and professional society in the field.