USDA : international macroeconomic data set from 1969 - 2020
FRED: Federal Reserve Economic Data provides 44,000 economic time series from 38 sources particularly there is data on banking and finance, population, employment, labor markets, business activity, prices, exchange rates etc.
U.S. Bureau of Labor Statistics (BLS): Principal source for federal data in the field of labor economics and statistics.
American Fact Finder: source for population, housing economic and geographic information and data.
Economic Policy Institute: Has long-term economic data for the U.S. that can be downloaded in Excel or zip formats.
US Foreign Aid Allocations: The US Overseas Loans and Grants Database (Greenbook) published by USAID provides the complete historical record of US foreign assistance by recipient country and program.
Urban Institute: provides data from research based on the nation’s social and fiscal challenges.
E. Scott Adler Data: dataset includes a wide range of economic, social and geographic information for every U.S. congressional district, from 1943-1998.