He was publisher of Débats de la législature du Québec from 1879 to 1890, and French-language parliamentary stenographer at the House of Commons of Canada from 1892 to 1917.

In 1897 Desjardins became increasingly concerned with the problem of usury and undertook three years of careful research and correspondence with the founders of cooperative savings and credit movements in Europe.

After failing to get a federal law passed in Ottawa that would provide a Canadian-wide framework for more such organizations, Desjardins turned his efforts, with the collaboration of journalists and priests, to founding more caisses.

At the time of his death in 1920, there were 187 caisses populaires in Québec (30,000 members and total assets of nearly $6 million), 24 in Ontario and 9 in the United States.

Alphonse and Dorimène Desjardins' home, where the first caisse populaire was launched, is now a center dedicated to his memory and has been visited by over 178,000 people from 115 countries since its opening in 1982.