Power was educated in Ireland, then studied law at Quebec City with Norman Fitzgerald Uniacke and then George Vanfelson, and was admitted to the Lower Canada bar in 1826.
In 1827, he was named clerk for the Vice Admiralty Court.
He was a captain in the Queen's Volunteers in the Eastern Townships.
In 1840, he was named to the Court of Appeals for Quebec district; in 1844, he was named to the circuit court and, in 1857, to the Quebec Superior Court for Montmagny district.