Teacher Resources: Economic Barometer
Gross Domestic Product (GDP) is the dollar value measure of all of the final goods and services produced within a country in a specific period, usually one year. The real GDP is the dollar value of the goods and services adjusted for inflation.
Changes in Real GDP are the best measures of the growth or decline of the economy.
http://www.bea.gov/national/ (Select link for "Current" dollar and "real" GDP)