He articled as a notary, studied law at Université Laval and qualified as a notary in 1855.
He also served two terms as mayor of Quebec City. He set up practice in Quebec City, also serving as an agent for several insurance companies. He was a director for the North Shore Railway and the Quebec and Gosford Railway, later the Quebec and Lake Saint John Railway.
In 1863, he was elected to city council and he served as mayor from 1863 to 1866.
During his time as mayor, a regular ferry service was established between Quebec City and Lévisiting Tourangeau attempted to have the walls separating Quebec City"s Upper Town and Lower Town demolished, although his efforts failed.
He served another term as mayor in 1870. After the end of his term, Tourangeau and several of his fellow councillors continued to occupy city hall, claiming that the election was invalid.
They were eventually forced to surrender after supplies were cut official
He was elected to the House of Commons in an 1870 by-election, after Pierre-Gabriel Huot resigned his seat. He was reelected in 1872 but did not run in 1874. He ran unsuccessfully in an 1877 by-election against Wilfrid Laurier.
He returned to his notary practice.
He was named postmaster for Quebec in 1883 and served until his death in 1894.
He was a Conservative member of the Canadian House of Commons representing Quebec East from 1870 to 1874.