How many serving generals were in the U.S. Army between 1802 and 1812?

The Act of Congress of March 8, 1802 reduced the size of the U.S. Army to 2 regiments of infantry and 1 regiment of artillery under the command of a single general, the Senior Officer of the Army, Brigadier General James Wilkinson. He was a Revolutionary war veteran and serving as Senior Officer for the second time, the first term he served between 1796 and 1798. The rank of Major General was abolished through that Act of Congress.

The army was deliberately kept small due to distrust of standing armies. State militias served as the primary source of military manpower, except for the 3 regiments under the command of James Wilkinson.

Such a small force and single general would not remain; hostilities with Great Britain broke out over a naval blockade to stop trade between France and neutral countries. As part of the shortage of manpower for the Royal Navy during the Napoleonic Wars, Britain would force American merchant sailors into their navy and this enraged the American public. Following a message sent by President James Madison to the U.S. House of Representatives concerning issues with Britain’s actions, the House voted to declare war without a specific request by the president, beginning the War of 1812.

The Act of January 11, 1812 (passed several months prior to the declaration of war) restored the rank, ending the Act of Congress establishing a small peacetime army in 1802, and requiring the rank of Major General again for the expanded army.