The limitations placed by Gen. Harney upon Lyon's assignment to command were aggravating. Hagner commanded the buildings, the arms, ammunition, and other stores, and the strong walls surrounding the grounds. Lyon commanded merely the men. He could not draw a musket, a cannon, or a cartridge for either, not even a hammer, a spade nor an ax, without a requisition duly approved by Harney. Nor could he change a single arrangement of the grounds without Harney's approval.
Lyon was almost nightly meeting with the Committee of Safety, and visiting the drill-rooms of the Home Guards, where he advised, encouraged and drilled the men. The Secessionists were extremely fearful that in some way he would manage to get the arms and ammunition, and besought Harney and Hagner to omit no precaution to prevent this.
When away from his Secessionist environment, Harney's soldierly instincts asserted themselves. Lyon's vigorous, uncompromising course was far more to his mind than the dull, shifty Hagner's.
One was zealous in the performance of his duty, and the other a red-tape bureaucrat, whose first thought always seemed to be to clog and hamper the men in the field. Harney had suffered too much from these "office fellows" to be especially enamored of them. Therefore he had moods, when he gave Lyon a free hand, which the latter made the most of until the General's mood changed.
During one of these Lyon had undermined the walls of the buildings, placed batteries, built banquettes for the men to fire over the walls, cut portholes, reinforced the weaker places with sandbags, and established a vigilant sentry system to prevent surprise.
The Secessionists were equally full of plans, though not of performances. Minute Men were organizing throughout the State to rush in at the given day by every train and overwhelm St. Louis, taking the Arsenal by sheer force of numbers. Many of the Captains of the large steamboats which carried on the trade between St. Louis and New Orleans were zealous Secessionists, and mooted plans for assailing the Arsenal on the river side with cannon mounted on boats, backed up by large crowds of men. But Gov. Jackson and his coterie still relied mainly upon inciting some form of riot in the city, which would allow Gen. Frost to get possession of the Arsenal with his Militia and "protect it from violence." Once in Gen. Frost's hands—then!
The Secessionists scored a point and carried dismay to the Unionists by securing an order from Gen. Scott for Capt. Lyon to attend a Court of Inquiry at Fort Leavenworth. While he was gone they might carry out their plans with comparative ease and safety. Blair, however, succeeded in getting Gen. Scott to revoke the order.
To find out precisely what the position of affairs inside the Arsenal was, and to spy out its defenses, a number of prominent citizens, among whom was James S. Rains, afterwards Brigadier-General in the Confederate army, calling themselves Grand Jurors for the United States District Court, presented themselves at the Arsenal and attempted an entrance. The Sergeant of the Guard held them awhile till he could communicate with Capt. Lyon, and they went away in anger.