In 1867, Brown ran for a seat in the House of Commons of Canada. As the leader of the Ontario Liberals, he also ran for a seat in the Legislative Assembly of Ontario. His intention was to become Premier but he failed to win election to either chamber. He was widely seen as the leader of the federal Liberals in the 1867 federal election. The Liberals were officially leaderless until 1873, but Brown was considered the party's "elder statesman" even though he had a seat in the House of Commons, and he was regularly consulted by leading Liberal parliamentarians. Brown was made a senator in 1873.