I have seen varying dates for the capture of the Baton Rouge Arsenal (Jan. 10, Jan. 11 or Jan.13 1861). Suffice to say it was taken by the state militia under Louisiana Governor Thomas Overton Moore before the Louisiana Legislature passed the Articles of Secession, which was on Jan. 26, 1861.
According to one source, the equipment was transported to Alexandria and processed over to Col. William Tecumseh Sherman, who was then superintendent of a miltitary school there (was to become LSU). Sherman, of course, was opposed to secession and reluctantly accepted the captured equipment. He refused to hide the material and felt it dishonorable and treasonous to continue his present actions. His conscience dictated that he resign.
Col. Sherman tendered his resignation to Gov. Moore in Alexandria. Sherman informed the governor that the capture of the Baton Rouge Arsenal before secession was an act of treason and the governor would be arrested and tried if he were captured during the war. Both men laughed and parted ways.
Despite the laughter, the seizure of the Baton Rouge Arsenal pre-dated the assault on Fort Sumter by several months and constituted the first serious act of hostility to Federal authority. It was recaptured by Union forces in August of 1862 and held for the balance of the war.