He attended the public schools and engaged in the manufacture of boots and shoes.
He served in the Massachusetts House of Representatives, and was elected as a Republican to the Fifty-first and to the four succeeding Congresses (March 4, 1889 – March 3, 1899). He served as chairman of the Committee on Banking and Currency (Fifty-fourth and Fifty-fifth Congresses). He was an unsuccessful candidate for reelection in 1898 to the Fifty-sixth Congress.
Walker resumed his former business pursuits, and died in Worcester on April 3, 1907.
His interment was in the Rural Cemetery. Walker Hall at Worcester Academy is named in his honor and service to the Academy.
He was a member of the common council of Worcester 1852–1854. Walker established the business of manufacturing leather in Chicago, Illinois in 1868.