With Claude-Jean Allouez, S.J., André built the Mission of St. Francis Xavier in what is now De Pere, Wisconsin.
He continued to serve as a missionary, evangelizing the Menominee, Potawatomi, and Winnebago tribes in the Green Bay, Wisconsin, area.
He relocated to Mackinac in 1682 and 1683, going on to teach at the Jesuit College in Quebec for several years.
André's ministry in the New World combined a great deal of missionary work as well as a number of years teaching philosophy and Latin.
At some time in Canada he compiled an important Algonkin and Ottawa dictionary and a small conversational manual which still exists.