He was a member of the Wisconsin State Senate and Assembly, representing Brown, Door, and Kewaunee counties.
While serving as district attorney, he was elected to represent Kewaunee County in the Wisconsin State Assembly in the 1865 session, running on the Democratic Party ticket.
He served a two-year term representing the 2nd State Senate district, which then comprised all of Brown, Door, and Kewaunee counties.
He retired in 1878 and moved to Manitowoc County, Wisconsin, to reside with his son's widow, Elizabeth Mallory Walker, and his grandchildren.
[4] Both of Walker's surviving sons' served as Union Army officers during the American Civil War.
His elder son, Charles H. Walker, was captain of Company K and later major of the 21st Wisconsin Infantry Regiment.