New York sent Benson as a delegate to the Continental Congress in 1784. Although he was reappointed in 1785, he did not attend sessions. In 1786, he was named by the Legislature to accompany Alexander Hamilton as a delegate to the Annapolis Convention, which issued a call for the United States Constitutional Convention held the following year. He returned to the Congress in 1787 and 1788, and in 1788 attended the New York state convention that ratified the United States Constitution.