The U.S. flag has undergone changes since 1777 and now contains 50 stars to represent states. The colors were chosen to represent purity, valor, and justice. Stars represent divine aspirations and stripes represent rays of light. The bald eagle was chosen as the national bird in 1782 to symbolize strength, courage, freedom, and immortality. Benjamin Franklin and others created the Great Seal of the U.S. in 1776 to represent independence. The Liberty Bell rang at the signing of the Declaration of Independence and has become a symbol of freedom. Uncle Sam became a symbol for the U.S. government from the supplier Samuel Wilson during the War of 1812.