Lyon, who as a soldier had naturally chafed under the insulting presence on the hills of a force hardly concealing its hostility under a thin vail of professed loyalty, at once resolved upon the capture of the camp. The more cautious of the Union men tried to restrain him. They argued that the camp would expire by legal limitation within a few days. To this Lyon opposed the probability that the Legislature would pass the military bill in some form and make the camp a permanent one.
Then, those timorous ones insisted that the forms of the law should be employed, and that the United States Marshal, armed with a writ of replevin to recover United States property, should precede the attack upon the camp. Lyon fretted under this; The writ of replevin was a tiresome formality to men who talked of fighting and were ready to fight; furthermore, if served and recognized, Frost might put off the Marshal with some trumpery stuff of no value. Still further came the news that Harney, with Gen. Scott's assistance, had reinstated himself in favor at Washington, and would return the following Sunday. It was now Wednesday, the 8th of May.
Above all, Lyon saw with a clearer insight than the strict law-abiders the immense moral effect of his contemplated action. Heretofore all the initiativeness, all the aggressiveness, all the audacity, had been on the side of the Secessionists. They were everywhere taking daring steps to the confusion and overthrow of the conservative Unionists, and so dragging with them hosts of the wavering. He longed to strike a quick, sharp blow to teach the enemies of the Government that they could no longer proceed with impunity, but must expect a return blow for every one they gave, and probably more.
On Wednesday evening, May 8, Capt. Lyon requested Mr. J. J. Witzig, one of the Committee of Safety, to meet him at 2 o'clock the next day with a horse and buggy. At the appointed hour Witzig went to Lyon's quarters and inquired for the "General," by which title Lyon was known after his election as Brigadier-General of the Missouri Militia. As he entered Lyon's room, Witzig saw a lady seated near the door, vailed and evidently waiting for some one. He inquired if she was waiting for the General to come in, and seating himself near the window awaited the coming of Lyon. A few minutes later the lady arose, lifted her vail, and astonished Mr. Witzig with the very unfeminine features of Lyon himself. Mrs. Alexander had loaned him the clothes, and succeeded in attiring him so that the deception was complete. Taking a couple of heavy revolvers, Gen. Lyon entered a barouche belonging to the loyal Franklin Dick, and was driven by Mr. Dick's servant leisurely out to Camp Jackson, followed by Mr. Witzig in a buggy. Lyon saw everything in the camp that he wished to see; noticed that the streets were named Davis Avenue, Beauregard Avenue, and the like; took in the lay of the ground, and returning toward the Arsenal, stopped and directed Witzig to summon the other members of the Committee of Safety to immediately meet him at the Arsenal.