He was born in Independence Township, Oakland County, Mich. on August 23, 1852, and attended the common schools in Clarkston and Detroit. He began teaching school in 1869, served as superintendent of schools in Waterford Township in 1875 and also as principal of the school at Waterford, Michigan. He went on to study law, was admitted to the bar in 1877 and graduated from the law department of the University of Michigan at Ann Arbor in 1878. He began legal practice in Pontiac, Michigan, where for six months he worked alone with considerable success, and then formed a partnership with Judge Levi Taft and Hon. Aaron Perry. Judge Perry retired from the firm during the second year of the partnership, but the connection between Judge Taft and Mr. Smith continued until the death of the former in 1897. He was prosecuting attorney of Oakland County from 1880-1884.

He served in the State senate 1885-1887, and was elected as a Republican to the Fifty-fifth and to the eight succeeding Congresses (March 4, 1897-March 3, 1915); chairman, Committee on District of Columbia (Sixtieth and Sixty-first Congresses). (He was known as the Mayor of District of Columbia --there wasn't always a mayor of DC as now-- also called Senator Sam.) He was responsible for rural route postage delivery being implemented. He did not stand for reelection to the Sixty-fourth Congress, but moved to Detroit in 1913 and continued the practice of law. He died in Detroit on June 19, 1931, and was buried in Oakwood Cemetery - Adrian, Lenawee County, Mich.