A veteran of the War of 1812, he served in the Legislative Assembly of Lower Canada from 1820 to 1830, and then as representative from Nicolet.
He was later released and returned to raising cattle, purchasing considerable land in Nicolet.
Proulx entered political life, being elected to the Legislative Assembly of Lower Canada for Buckingham in 1820 and serving until 1830, when the riding was divided.
Proulx represented Nicolet until the suspension of the constitution following the Lower Canada Rebellion.
In the 1830s Proulx supported the Ninety-Two Resolutions and attempted to organize armed revolt in his county, but with little success.