Stephenson worked in lumbering activities in the eastern U.S. for several years, principally in Maine, close to Canada. In 1845 he moved to Wisconsin, where for a time he managed absentee timber properties, but soon entered the lumber business for himself. In 1858 he settled permanently in Marinette, where he steadily expanded his lumbering operations, especially during the Civil War. Although Stephenson suffered heavy losses in the Peshtigo Fire of 1871, he recouped. He was one of the wealthiest lumbermen in the Great Lakes area, with real-estate holdings in Marinette, Green Bay, Milwaukee, and the booming town of Chicago, and throughout the Great Lakes. He also owned vast acreages of pine lands in northern Wisconsin and Michigan which were yet to be harvested.
Political career
Stephenson joined the Republican Party, which was popular among his class in the northern tier of states. His wealth and economic power made him a powerful figure in local and state politics. He was elected to several offices, including town supervisor, county board chairman, and justice of the peace. Next Stephenson was elected as a member of the Wisconsin State Assembly. In 1882, he was elected to the Forty-Eighth Congress, and then reelected to the Forty-Ninth and Fiftieth Congresses. He represented Wisconsin's newly created 9th congressional district. He was not a candidate for re-election in 1888. In 1899 he was unsuccessful in his bid to gain election by the state legislature as a United States Senator from Wisconsin.
In 1900 he threw his support and substantial financial backing behind Robert M. La Follette, Sr., in his campaign for the Wisconsin governorship, and for a number of years was a prominent adviser to the Progressive faction of the Republican party, and a liberal contributor to its campaign funds. In the 1904 progressive-stalwart split, Stephenson was chosen by the "gymnasium convention" as one of the progressive delegates to the Republican national convention along with La Follette and William D. Connor. Although the national convention refused to accept the credentials of the Progressive delegation, the La Follette forces were recognized as the legal Republican ticket by the Wisconsin Supreme Court. In 1901 Stephenson established the Milwaukee Free Press, providing Progressive-Republicans with a metropolitan newspaper, and competition for the Stalwart-controlled Milwaukee Sentinel. In 1907 Stephenson sought the U.S. Senate seat made vacant by the resignation of John C. Spooner and, after a brief deadlock, was elected by the Progressive-controlled state legislature. In 1908 he ran for renomination in the Republican primary, was opposed by La Follette, but despite this opposition won the nomination through the aid of the state chairman of the Republican party William D. Connor and lavish use of his personal wealth, and was re-elected by the legislature in 1909. Although his election was twice blocked by fraud investigations in both the state legislature and the U.S. Senate, Stephenson was eventually vindicated and resumed his seat in the Senate, serving from May 1907, to March 1915. Stephenson holds the distinction of being the oldest elected freshman United States Senator; he was 77 when he took office. In 1909 Stephenson purchased a prized Holstein cow as a gift for the 27th President of the United States, William Howard Taft. The cow was named Pauline Wayne and she became the last presidential pet cow. Pauline Wayne lived and grazed on the White House lawn.
Retirement
After returning from Washington in 1915, Stephenson retired to his home in Marinette, where he remained until his death on March 15, 1918. Noted for his local philanthropies in Marinette, a park, street, and memorial library are named in his honor. His younger brother, Samuel Merritt Stephenson, served as a U.S. Representative from Michigan.
