During World War I, Henderson served in the United States Navy.
He remained in private practice until 1931, when he was appointed Assistant Attorney General of Maryland, a position he served in until 1941.
From 1943 to 1944, Henderson served as a judge of the Supreme Bench of Baltimore City.
He remained in that position until 1964, when he briefly served as chief judge of the court.
After his tenure on the Court, he served as a delegate from Anne Arundel County to the Maryland Constitutional Convention of 1967.