[1] While attending college, Walker taught school in Orleans, Massachusetts and served as principal of West River Academy in South Londonderry, Vermont.
[1] After graduation, Walker was principal of the academy in Little Falls, New York, and began the study of law with Arphaxed Loomis.
[1] In August 1862, Walker enlisted for the American Civil War as a member of the Union Army's 16th Vermont Infantry.
[1] He was commissioned as a captain and selected to command the regiment's Company C, but an attack of typhoid fever followed by a lengthy convalescence led to his discharge in October.
[1] Later that year he was appointed an associate justice of the Vermont Supreme Court, and he served until ill health forced him to resign in 1887.