Mason prepared the first draft of the Virginia Declaration of Rights in 1776, and his words formed much of the text adopted by the final Revolutionary Virginia Convention. He also wrote a constitution for the state; Thomas Jefferson and others sought to have the convention adopt their ideas, but they found that Mason's version could not be stopped. During the American Revolutionary War, Mason was a member of the powerful House of Delegates of the Virginia General Assembly but, to the irritation of Washington and others, he refused to serve in the Continental Congress in Philadelphia, citing health and family commitments.