Dr. Eustis, the Secretary of War, was forced to resign to appease the popular wrath and was succeeded by John Armstrong, who had been Minister to France under President Jefferson, and was appointed a brigadier general at the beginning of the war. Armstrong divided the country into nine military districts to each of which a general officer of the United States army was assigned whose duty it was to superintend all the means of defence within his district. This was done to prevent any difficulty arising from the interference of governors of states opposed to the war.
The districts were composed as follows: 1 Massachusetts and New Hampshire. 2 Rhode Island and Connecticut. 3 New York from the sea to the Highlands and the State of New Jersey. 4 Pennsylvania from its eastern limit to the Alleghany Mountains and Delaware. 5 Maryland and Virginia. 6 The two Carolinas. 7 The States of Tennessee Louisiana and the Mississippi Territory. 8 Kentucky Ohio and the Territorial governments of Michigan Indiana Illinois and Missouri. 9 Pennsylvania from the Allegheny Mountains westward New York north of the Highlands and Vermont. [Source]