Porter had held various town offices (such as tax assessor and school superintendent), and was chairman of the town's board of supervisors[2] when he was elected in 1872 for the 26th Wisconsin Legislature (1873 session), from the 3rd Columbia County Assembly district (the Towns of Arlington, Caledonia, Dekorra, Leeds, Lodi, Lowville, Pacific, West Point and Wyocena) as a Republican, succeeding fellow Republican Jacob Low.
He was assigned to the standing committee on engrossed bills; and his son Frank (age 10) was employed as a messenger during the Assembly session.
When the 1880 History of Columbia County was published, John and Ann Porter were still living on their 400-acre farm with their three youngest sons.
[4] In November 1881 he was assigned to Columbia County's petit jury for the coming year.
John died in the family home in Portage on June 16, 1897, and was buried in Pacific; Ann would live until 1902.