Alexander McDougall was a Scottish-born American seaman, merchant, a Sons of Liberty leader from New York City before and during the American Revolution, and a military leader during the Revolutionary War. After the onset of the French and Indian War in 1756, McDougall became commissioned by the crown as a merchant privateer. In 1763 McDougall gave up the seafaring life. The war had ended, his wife Nancy died, as did his father. When revolutionary fervor grew with resistance to the Stamp Act, McDougall became active in the Sons of Liberty, and later was a leader in the movement in the colony of New York.McDougall became the street leader of the Sons of Liberty, and organized continued protests until the city became under de facto control of the Patriots in 1775. On 30 June 1775, McDougall became a commissioned colonel of the 1st New York Regiment by an act of the New York Provincial Congress. Eventually, McDougall would rise the rank of Major General in the Continental Army.

Soon after his commission, McDougall's troops were sent north to take part in the invasion of Quebec (1775), among them were two of McDougall's sons After the Continental Army left New York City, they traveled north and made an initial stand against the British near the village of White Plains. Here, McDougall helped to hold off the British and allow for the main body of the army to avoid conflict. Throughout the war, McDougall was an outspoken advocate for the Continental Army and for better conditions for its soldiers. In the winter of 1783 he was at the head of the committee of army officers who the bore complaints about pay from Newburgh to Congress. McDougall was also involved in the establishment of an American navy in 1776. In 1780, he was elected as delegate to the Continental Congress. He spent only 37 days in Congress, however, he was soon nominated to serve as the Secretary of Marine.