He served as the presiding officer for the last year and a half. He also served as an associate justice of the Pennsylvania Supreme Court.
Morton’s greatest accomplishment was his service as a delegate from Pennsylvania to the Continental Congress from 1774–1777. He represented the state at the Stamp Act in New York. Morton was also instrumental in the final outcome of the debate over the Declaration of Independence. He changed his vote on July 4, 1776, to side with Benjamin Franklin and James Wilson to vote for independence. This change pushed the Pennsylvania delegation to vote for independence, and the Pennsylvania vote tipped the vote of the Continental Congress in favor of independence. John Morton became ill and died in 1777. He is buried in the Old St. Paul’s Cemetery, Chester, Pennsylvania.