My g grandmother was born either 1840 or 1842 in Belleville, Ont. She married Joseph Lerance. They were illiterate and the name is obviously an Anglophone's version of Laurence or similar French name. They were farmers in Hungerford township, Hasting county, near present day Tweed.
She was probably married in 1860; her first child was born in 1861. They left Ontario and moved to Minnesota in 1877.
The 1871 census shows them as all having been born in Ontario, so I imagine the Lerance and the St. Louis family had moved there from Quebec sometime earlier.