In 1692, he traveled to France with Pierre Le Moyne d'Iberville and was stationed in 1693 at Fort Nashwaak, the capital of Acadia.

In 1704, he returned to Acadia, where he helped orchestrate raids against English settlements and worked to convince the Abenakis to resettle closer to French territories.

In the winter of 1704-05, he led a band of Abenakis to Newfoundland to replicate d'Iberville's 1696 expedition under the command of Daniel d'Auger de Subercase.

Montigny was awarded the Order of Saint Louis in 1712 and, in 1721, was given command of a frontier fort on Green Bay.

Jacques Testard de Montigny is remembered for his military service in New France and his interactions with Indigenous leaders.