When the Continental Congress was established, it appointed a Commander-in-Chief and set about to raise an army. But there was no War Department back then. Instead, Congress ran the war by committees, which were usually established on an ad hoc basic to deal with specific issues such as supply or disciplinary matters. Later, in June 1776, Congress established a committee called “Board of War and Ordnance.” Absorbing all of the work of the various committees, the Board found itself meeting sometimes twice a day. Its chairman, John Adams, lamented that the duties kept him in “continual employment, not to say drudgery,” until he left Congress. In July 1777, Congress created a Board of War, which gradually included military officers, including Major General Thomas Mifflin and Colonel Timothy Pickering. Later, Saratoga hero Horatio Gates would become its Chairman, and Thomas Conway, of Conway Cabal fame, the Inspector General.
One of the major problems was the overall decentralized nature of war administration. For instance, the Board or War might pledge supplies to troops, but Congress had no money or credit to pay for it. General Henry Knox noted that it was “absolutely necessary that the Head of every Department…be accountable to the Board of War.” In November 1779, the various staff departments did end up under the Board or War. By February 1781 a resolution for creation of a War Department passed, creating the office of Secretary at War.
One leading candidate was John Sullivan of New Hampshire, but he opted out because of poor health. Alexander Hamilton’s name came up, but he was ruled out because of insufficient rank. Other candidates included Generals Schuyler and McDougall, Major General Nathaneal Greene, and Henry Knox. Eventually General Benjamin Lincoln got the job, not so much on the basis of talent, but because he had the best overall relations with Congress and his fellow officers, and his apparent lack of personal ambition appeased those concerned about growth of the military and centralized power.
For more information, see Harry M. Ward, The Department of War, 1781-1795. Westport, CT: Greenwood Press. 1981.