Johnson was born in
Kingston, Ontario, which was then part of
Upper Canada. His father died just two years after his birth. He had been a
British Army sergeant under
Wellington in the
War of 1812, who remained in Canada after the war. His mother was daughter of an
American Revolutionary War volunteer. After attending
Rock River Seminary, Johnson moved to
Prairie du Chien, Wisconsin, in 1848. Here, he began the study of law, and, in 1849, was admitted to the
State Bar of Wisconsin. He practiced law in Prairie du Chien for several years, but, in 1854, he purchased a stake in the Prairie du Chien
Courier, and soon became its sole proprietor and editor. He returned to the practice of law in 1856, forming a partnership with W. R. Bullock, a nephew of
John C. Breckinridge. The partnership was broken by the
American Civil War, when Bullock joined with the Confederacy. After serving in the Assembly as a Republican, he became associated with the
Liberal Republican faction in the so-called "Greeley movement", named for
Horace Greeley. He was a delegate for Wisconsin to the
1872 Liberal Republican convention in
Cincinnati which nominated Greeley for president. Greeley was subsequently also nominated by the Democratic Party, and, from that point on, Johnson became affiliated with the
Democratic Party. He served in various local offices over the next decade, as
city attorney and member of the Milwaukee School Board. ==Electoral history==