When Joseph Lamontagne was born on 24 December 1823, in Bécancour, Bécancour, Quebec, Canada, his father, Francois Lamontagne, was 29 and his mother, Anna Marie Legare, was 25. He married Louise Helene Harrington on 4 February 1856, in Bécancour, Nicolet, Quebec, Canada. They were the parents of at least 4 sons and 4 daughters. He died on 12 June 1910, in Lewiston, Androscoggin, Maine, United States, at the age of 86, and was buried in Lewiston, Androscoggin, Maine, United States.