John G. Nicolay, The Outbreak of Rebellion

[117] “After learning,” wrote Jefferson Davis, in reply, April 23d, “as well as I could from the gentlemen accredited to me, what was most needful for the attack on the arsenal, I have directed that Captains Green and Duke should be furnished with two twelve-pounder howitzers and two thirty-two-pounder guns, with the proper ammunition for each. These, from the commanding hills, will be effective, both against the garrison, and to breach the enclosing walls of the place.”

Encouraged by this co-operation, the Governor, as his next step, instructed one of his militia generals, D. M. Frost, a West Point graduate, to assemble the available organized and equipped volunteer companies of the State in a camp of instruction at St. Louis. The Governor had also convened his Rebel Legislature to meet in extra session on May 2d. The day following, May 3d, began the assembling of the militia in “Camp Jackson,” so named in honor of the Governor. Two regiments and part of a third soon arrived; and though some of the companies were either without political bias, or of Union sentiment, a general spirit of secession pervaded the camp, and its avenues were christened “Davis” and “Beauregard.” The object of the organization soon became unmistakably known to Lyon, Blair, and the Union Safety Committee, who, by the aid of skilful detectives, gained information of all its movements. On the night of May 8th, the cannon, ammunition, and some muskets furnished by Jefferson Davis, were landed from a New Orleans steamer, in boxes marked “marble,” and immediately loaded upon drays and hauled out to the camp.

Under this threatening disclosure, the Unionists felt they could no longer dally with the conspiracy. Already three weeks before, the United States Arsenal at Liberty, Mo., had been robbed of its arms by the disunionists, and Jeff.