Richard Montgomery began his military career in the British army and gained experience in North America during the Seven Years' War. He served in campaigns against French possessions, including the operations around Louisbourg, and later reached the rank of captain. After leaving the army he settled in New York, married into the Livingston family, and established himself as a landowner. The imperial dispute gradually drew him into the colonial resistance.

In 1775 he joined New York's Provincial Congress and accepted a commission as brigadier general in the Continental Army. Assigned to the northern campaign under Philip Schuyler, Montgomery took effective command when Schuyler's illness forced his withdrawal. He advanced through the Richelieu corridor, directing the siege of the British position at Saint-Jean. Its surrender opened the route to Montreal, which American forces occupied in November.

The campaign required negotiation alongside military operations. Montgomery sought supplies, managed short enlistments and discipline problems, and tried to avoid alienating Canadian inhabitants. Occupation did not ensure lasting local support. With winter approaching, he moved downriver to join Benedict Arnold's force outside Quebec, where the defenders remained secure. The Americans faced dwindling manpower, disease, severe weather, and the approaching expiration of many soldiers' enlistments.

Montgomery and Arnold decided to assault the city during a snowstorm on December 31, 1775. Montgomery led one attacking column along the riverfront and was killed by defensive fire before it could break through. Arnold was wounded, and much of the force entering the lower town was captured. The attack failed, although an American siege continued for several months before retreat in 1776. His death made him a commemorated Revolutionary figure. Congress ordered a monument, and his remains were transferred to New York. Montreal and Quebec defined his short Continental career.