During the war, he served as a major, colonel, and brigadier general. In 1776, he led 14 units to New York City to help defend the city with General Israel Putnam. Then in December, he was given command of the 6th Connecticut Militia brigade. He participated in the Battles of Saratoga (September 19-October 7, 1777). Wolcott displayed excellent leadership during the battles. In one example, on his own volition he led a force of 309 cavalry to reinforce General Horatio Gate's army along the Hudson River in Northern New York. As a result of his efforts, he was promoted to major general in command of all Connecticut militia. His primary task in this role was to defend the Connecticut seacoast against British raids.
After the war, Wolcott was elected lieutenant governor in 1786 and then governor in 1796. He died the following year in December and is buried in East Cemetery here in Litchfield.