LEBANON, ILL., May 11, 1861.

Honorable SIMON CAMERON, Secretary of War:

Two thousand troops, under Captain Lyon, surrounded Camp Jackson yesterday; took 1,200 State troops, with camp equipage, into custody. Cannon stolen at Baton Rouge were recovered. Prisoners were offered release on parole but refused it. They were marched to arsenal an hour after surrender. Excited populace grossly outraged U. S. troops, and finally fired on them. The fire was returned, but immediately suppressed by captain Lyon; 15 or 20 populace, 3 U. S. troops wounded. Intense excitement in the city. Four thousand home guards under arms patrolling streets all night. Habeas corpus writs will be applied for to-day to release prisoners, but will be disregarded by Lyon. Many prisoners marched through streets hurrahing for Jeff. Davis. Left arsenal at midnight; will arrive Monday at Washington. Our friends fear return of Harney to Saint Louis and protest against it.

J. B. EADS.

WAR DEPARTMENT,

Washington, D. C., May 11, 1861.

J. T. SANDERSON, Chief Clerk:

The following has just been received from Saint Louis:

General Frost's brigade Missouri militia at Camp Jackson surrendered unconditionally at demand of Federal troops. Release on parole offered but declined on ground that to take oath would imply they had been in arms against U. S. authorities which they [denied]. While State troops were drawn up between two lines Union volunteers, stones were thrown, pistols were shot, one of which entered leg of Captain Blandowsky, who, while failing, gave command to fire. Twenty persons, including two women and several children, killed and many others wounded. Great excitement, and republican newspapers threatened by mob.

P. S. SANDERSON.

SAINT LOUIS ARSENAL, May 11, 1861.

Colonel L. THOMAS, Adjutant-General U. S. Army.

SIR: In compliance with instructions from your office of the 30th ultimo, I accepted, swore in, and armed 3,436 men and 70 officers of the loyal citizens of Saint Louis, as a reserve corps, for the protection of Government property and enforcement of its laws, on the 7th and 8th instant, and should probably have still further proceeded in receiving further offers but for events to which I will now advert. The steamer J. C. swan arrived at Saint Louis on the night of the 8th, with a large supply of miliary stores, including, as I was informed, muskets, ammunition, and cannon taken on board at baton Rouge, and there obtained from the arsenal. The boat arriving in the night great industry was used to transport these stores during the night (and before being likely to be exposed in the morning) to the camp of what is called the State militia, and which is made up for the most part of what has for a long time been known as a body of rabid and violent opposers of the General Government, and who have, during this time, been a terror to all loyal and peaceful citizens.

Their extraordinary and unscrupulous conduct, and their evident design, and of the governor of this State, to take a position of hostility