It is for the most part made up of those Secessionists who have openly avowed their hostility to the General Government, and have been plotting at the seizure of its property and the overthrow of its authority. You are openly in communication with the so-called Southern Confederacy, which is now at war with the United States; and you are receiving at your camp, from said Confederacy and under its flag, large supplies of the material of war, most of which is known to be the property of the United States. These extraordinary preparations plainly indicate none other than the well-known purpose of the Governor of this State, under whose orders you are acting, and whose purpose, recently communicated to the Legislature, has just been responded to in the most unparalleled legislation, having in direct view hostilities to the General Government and cooperation with its enemies. In view of these considerations, and of your failure to disperse in obedience to the proclamation of the President, and of the eminent necessities of State policy and welfare, and the obligations imposed upon me by Instructions from Washington, it is my duty to demand, and I do hereby demand of you, an immediate surrender of your command, with no other conditions than that all persons surrendering under this demand shall be humanely and kindly treated. Believing myself prepared to enforce this demand, one-half hour's time before doing so will be allowed for your compliance therewith. Very respectfully, your obedient servant, N. LYON, Captain, 2d United States Infantry, Commanding Troops. There were a few anxious minutes following this, but it must be said to Frost's credit as a soldier that he promptly recognized the situation and acted upon it. Soon a horseman rode out from the camp, and approaching Lyon handed him the following note: 77 Camp Jackson, Mo., May 10, 1861. Capt. N. Lyon, Commanding U. S. Troops. Sir: I, never for a moment having conceived the Idea that so illegal and unconstitutional a demand as I have just received from you would be made by an officer of the United States Army, am wholly unprepared to defend my command from this unwarranted attack, and shall therefore be forced to comply with your demand. I am, sir, very respectfully, your obedient servant, D. M. FROST, Brigadier-General, Commanding Camp Jackson, Missouri Volunteer Militia. Lyon read it, turned to his second in command and remarked: "Sweeny, they surrender."