He received private education before attending the College of William and Mary, which he graduated from in 1764.

He was a neighbor and classmate at William and Mary of Thomas Jefferson and they remained close friends until the elections of 1804-1805.

He was in the Continental Army, serving in 1777 as an aide-de-camp to General George Washington, holding the rank of colonel.

When William Grayson died in 1790, Walker was appointed to the United States Senate to serve from March 31 to November 9 of that year, when a successor was elected by the Virginia General Assembly.

Thomas Jefferson’s attempted seduction of his wife, which almost led to a duel, and was fodder for the Federalist Press, is discussed in Dumas Malone’s Jefferson the Virginian (Boston, Little Brown and Company, 1948 Appendix III pp 447-451).