Returning from the War, he taught school, and published the Centerville (Iowa) Citizen from 1865 to 1874. He served as member of the Iowa House of Representatives in 1866 and 1867, and in the Iowa Senate, representing the 4th District, in 1868 and 1869. In 1869 he was elected as Lieutenant Governor of Iowa, starting his term in 1870.
In the 1870 Republican district convention for Iowa's 4th congressional district, Walden upset incumbent Fourth District Congressman William Loughridge in the race for the Party's nomination for Loughridge's seat.[4] Walden won the general election,[5] and served in the 42nd United States Congress from March 4, 1871 to March 3, 1873. However, when Walden ran for renomination in 1872 (in what was reapportioned in 1871 as Iowa's 6th congressional district), Loughridge turned the tables on Walden, ousting Walden.[6]
After his defeat, Walden engaged in agricultural pursuits and coal mining in Centerville.
In 1890 he was again a member of the Iowa House from Appanoose County.[1] He returned to Washington, D.C. in 1889 when he was appointed chief clerk in the office of the Solicitor of the Treasury, and served until his death in Washington on July 24, 1891. He was interred in Oakland Cemetery in Centerville, Iowa.