a bit slow please, it's for european level A2.
The Declaration of Independence
The text which declared the 13 colonies were independent from Britain was mainly written by Thomas Jefferson. It was adopted on July 4, 1776 in Philadelphia and signed by the Founding Fathers of the United States a few days later. But it was only after a long war that the USA really became independent in 1783.
After the war ended, the US Congress moved out of Philadelphia and settled in New York City. But philadelphians wanted the Congress to move back to Philadelphia or Pennsylvania. In 1790 Philadelphia was selected to be the temporary capital of the United States for 10 years before Washington DC was chosen as a permanent capital.