He served in the New Jersey General Assembly from 1780 to 1784, and was a master in chancery in 1790. He was a member of the New Jersey Legislative Council (now the New Jersey Senate) in 1793 and 1794, serving as Vice President of that body, and in 1793 and 1794 he was Acting Governor of New Jersey.
Henderson was surrogate of Monmouth County in 1776, and a member of the provincial council in 1777. He was elected as a delegate to the Continental Congress, November 17, 1779, but declined to serve on December 25, 1779.