Some of the facilities were maintained only skeleton crews or custodians. Others had more personnel but surrendered in the face of overwhelming opposing forces. At that time the U.S. Army consisted of only around 16,000 personnel and most were stationed on or near the frontier. There were no significant international threats.
Some of the major events before the shelling of Fort Sumer are listed below.
The U.S. Arsenal at Baton Rouge is taken over by La. state forces prior to formal secession on Jan. 26
"Task Force Walton" disembarked the next morning at Baton Rouge. Upon going ashore, Walton's troops rendezvoused with militia units from the capital city. Thus augmented, the Louisianians, now numbering some 600 strong, proceeded to the arsenal and barracks, which they surrounded.4
JAN 26, 1861, Louisiana officially secedes