Preference programs are tools that the U.S. government uses to assist countries usually in the developing world, which is provided through an enhanced trading relationship with the United States. One of the oldest programs is the Generalized System of Preferences, which was founded in 1976 and offers duty-free treatment for more than 4,650 products from 144 designated countries and territories throughout the world. Another highly successful program is the African Growth and Opportunity Act, which was enacted in 2000, and also allow duty-free entry of goods from countries in Sub-Saharan Africa.