A series of acts in 1774 further angered the colonies; activists called for a general congress and they agreed to meet in Philadelphia. The First Continental Congress was held in September in Carpenters' Hall. After the American Revolutionary War began in April 1775 following the Battles of Lexington and Concord, the Second Continental Congress met in May at the Pennsylvania State House. There they also met a year later to write and sign the Declaration of Independence in July 1776. Philadelphia was important to the war effort; Robert Morris said,