Philadelphia hosted the First Continental Congress in 1774, before the Declaration of Independence was adopted.
Delegates from 12 of the 13 colonies met at Carpenters' Hall in Philadelphia from September 5 to October 26, 1774. Georgia did not attend. The meeting responded to Britain's Intolerable Acts, punitive measures imposed after the Boston Tea Party.
The congress adopted the Continental Association, which organized a boycott of British goods, and sent a petition to King George III. It did not declare independence. The following year, the Second Continental Congress met in Philadelphia after fighting began and eventually directed the war effort.
Boston is closely linked to the causes of the Revolution, including the Boston Tea Party and the Boston Massacre, but it did not host the First Continental Congress. Philadelphia also hosted the Second Continental Congress and the Constitutional Convention.