In response to Governor Jackson’s order directing the military in certain districts to go into encampments for the purpose of improvement in the tactics of war, a camp had been formed at Lindell’s Grove, in the suburbs of St. Louis, called “Camp Jackson.” On the 4th of May it was inaugurated, under the charge of General D. M. Frost, and within a week numbered 800 men. Having received intelligence that it was the purpose of Captain Lyon to break up this encampment, General Frost addressed him a letter, dissuasive in its tone—disclaiming any intention on the part of himself and men of hostility to the Government, and containing an offer to preserve the public peace and guard the property of the United States.

The answer to this, was the surrounding of the camp by 5,000 Federal troops, and the following notice from Captain Lyon:

“Sir,—Your command is regarded as hostile towards the Government of the United States. It is, for the most part, made up of those who have avowed their hostility to the General Government, and have been plotting for 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 the said Confederacy and under its flag, large supplies of 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 by that body in the most unparalleled legislation, having in direct view hostilities to the General Government and co-operation with its enemies.”

Actuated by these considerations, and also by the failure to break up the camp, in obedience to the Presidential Proclamation of April 15th, Captain Lyon demanded its immediate surrender. After a hasty consultation with his officers, General Frost complied, and the place was surrendered unconditionally. But when the result was announced to the troops, it was received with the wildest yells, curses and groans. Some railed out against treachery, but the more loyal were rejoiced at the prospect of escaping from what they denominated a school of secession. Numbers of outsiders, also, when the news became known, rushed into the camp and gave loud voice to their feelings of indignation. The camp had in reality become a vast mob. Hurrahs for Jeff. Davis were given—many of the now disarmed soldiers joining in them. The United States troops were insulted in every possible manner, and rowdyism ruled the hour triumphantly. Officers had broken their swords and privates their guns before surrendering them. The task of marching the men out was a work of great difficulty, but at last it was accomplished, and the prisoners surrounded by two files of loyal troops. This act brought the fury of the mob to a climax, and when most of the troops had left, the few German soldiers that brought up the rear were attacked by the crowd, and showers of stones rattled upon them. The Federals presented their muskets, for the purpose of intimidating the mob, but without avail. The order to fire at length became necessary. It was given and executed with terrible effect, and the swiftly retreating mob left behind them from thirty to forty of their number, either dead or lying on the ground weltering in blood.

Many of the prisoners took the oath of fidelity to the Constitution and the laws, and were set free. A large amount of arms, ammunition, stores, camp equipage and stock was seized.

The event roused the secessionists in the city of St. Louis to the highest fury, and the night was made hideous by bloody encounters, in which several lives were lost.

The Legislature, then in session at Jefferson City, alarmed by these vigorous measures on the part of the Government, passed, the same afternoon, a “Military Bill,” authorizing the Governor to call out and equip the State militia, and appropriating all the available funds of the State for that purpose, in addition to the issuing of bonds to the amount of $1,000,000, and authority to borrow $500,000 from the State banks. The bill also gave to the Governor supreme authority in all military matters, and subjected every able-bodied man in the State to such authority, under penalty of $150 fine. The telegraph was seized by order of Governor Jackson, and the bridges on roads leading from St. Louis destroyed, from fear that Federal troops might reach Jefferson City by railroad and arrest the conspirators.

The loyal citizens of St. Louis trembled for their safety—fearful alike of an uprising of the secessionists in their midst and invasion from without. The “Home Guard” was organized—a reserve of volunteers proceeded to the arsenal for arms, and to take the oath of fealty, and other measures adopted for defence. On the afternoon of the 11th, a body composed mostly of Germans was assailed by a mob on their return from the arsenal. A fierce struggled ensued, and several were killed on either side.

The following day Brigadier-General Harney, of the regular army, reached St. Louis, and assumed command of the Military Department. Being himself a citizen of Missouri, and enjoying the confidence of the people in a very large degree, his presence produced a marked and salutary effect. By proclamation he demonstrated the madness and futility of any attempt to withdraw the State from her allegiance, and gave warning that any disturbance would be promptly suppressed. On the 14th he issued a second proclamation, declaring the “Military Bill” in conflict with the Constitution and laws of the United States, and therefore a nullity—equivalent to an ordinance of secession, and cautioned all good citizens against obeying it. The geographical position of the State, and her best interests, he asserted, rendered it absolutely necessary that she should remain in the Union, no matter what might be the position of the cotton States; and he emphatically declared that the whole power of the United States would be exerted, if necessary, to keep her within the national domain.

But secession influences were exceedingly active in almost all parts of the State, and the fact that the Governor and members of the Legislature were disorganizers, occasioned great apprehension in regard to her future destiny. The neighboring States of Iowa, Illinois, and Kansas made tender of liberal aid to the loyal men of Missouri, whenever required, to maintain their rights and their freedom. The secessionists now threw off their disguise, and resorted to violent aggressions and bitter persecutions of Union men. Many loyal citizens of Potosi, Washington county, seventy miles from St. Louis, were driven from the town, and their property injured or appropriated by the rebels.