After the failure of the Convention to unite Missouri with the Confederacy, Governor Jackson overhauled the militia laws, and, under their sanction, issued a call for a muster of militia near St.Louis.This militia assembled at Lindell Grove, in the suburbs of St.Louis, and a military camp was established, under the name of "Camp Jackson." Though ostensibly an innocent affair, this camp was intended to be the nucleus of the army to hoist the Rebel flag in the State.

The officers in command were known Secessionists, and every thing about the place was indicative of its character.
The Governor of Louisiana sent, from the arsenal at Baton Rouge, a quantity of guns and munitions of war, to be used by the insurgent forces in Missouri.

These reached St.Louis without hinderance, and were promptly conveyed to the embryonic Rebel camp.

Captain Lyon, in command of the St.Louis Arsenal, was informed that he must confine his men to the limits of the United States property, under penalty of the arrest of all who stepped outside.

Governor Jackson several times visited the grounds overlooking the arsenal, and selected spots for planting his guns.