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.  Every thing was in preparation for active hostility.

The Union people were by no means idle.  Captain Lyon had foreseen the danger menacing the public property in the arsenal, and besought the Government for permission to remove it.  Twenty thousand stand of arms were, in a single night, loaded upon a steamer and sent to Alton, Illinois.  They were conveyed thence by rail to the Illinois State Arsenal at Springfield.  Authority was obtained for the formation of volunteer regiments, and they were rapidly mustered into the service.

While Camp Jackson was being formed, the Union men of St. Louis were arming and drilling with such secrecy that the Secessionists were not generally aware of their movements.  Before the close of the day Captain Lyon received permission for mustering volunteers; he placed more than six hundred men into the service.  Regiments were organized under the name of “Home Guards,” and by the 9th of May there were six thousand armed Union men in St. Louis, who were sworn to uphold the national honor.

Colonel Francis P. Blair, Jr., commanded the First Regiment of Missouri Volunteers, and stood faithfully by Captain Lyon in all those early and dangerous days.  The larger portion of the forces then available in St. Louis was made up of the German element, which was always thoroughly loyal.  This fact caused the Missouri Secessionists to feel great indignation toward the Germans.  They always declared they would have seized St. Louis and held possession of the larger portion of the State, had it not been for the earnest loyalty of “the Dutch.”

In the interior of Missouri the Secessionists were generally in the ascendant.  It was the misfortune of the time that the Unionists were usually passive, while their enemies were active.  In certain counties where the Unionists were four times the number of the Secessionists, it was often the case that the latter were the ruling party.  The Union people were quiet and law-abiding; the Secessionists active and unscrupulous.  “Peaceably if we can, forcibly if we must,” was the motto of the enemies of the Republic.

In some localities the Union men asserted themselves, but they did not generally do so until after the first blows were struck at St. Louis.  When they did come out in earnest, the loyal element in Missouri became fully apparent.

To assure the friends of the Union, and save Missouri from the domination of the insurgents, it was necessary for Captain Lyon to assume the offensive.  This was done on the 10th of May, resulting in the famous capture of “Camp Jackson.”