He commenced to study law in Scotland, but came to Dunedin aged 19 in 1861, arriving on the Robert Henderson on 8 October.

After Rachel's death in 1878, Stewart married Mary Thomson; they produced one child, a daughter.

In 1863, when the Otago and Southland district was constituted under the Supreme Court Act, Richmond became a judge and Stewart joined the office of Prendergast, Kenyon and Maddock.

[2][4] The resignation of Robert Stout triggered a by-election in the City of Dunedin electorate.

Stewart won the 14 July 1879 by-election with a majority of 163 votes over his great friend Charles Reeves and entered Parliament.

[9] Stewart retired from Parliament in 1890 at the end of the electoral term, and was appointed to the Legislative Council.

[10] He was appointed from 22 January 1891 as one of seven new members (including Harry Atkinson himself) appointed to the council by the outgoing fourth Atkinson Ministry; a move regarded by Liberals as a stacking of the upper house against the new government.

Stewart Jr later became Mayor of Dunedin[12] and his sister Mary acted as his Lady Mayoress.