After a quick search of the Naval OR's, Vol. 23, page 249 it is as I suspected, there was a Louisiana side of the Missisippi land component of the Union Naval Blockade at Vicksburg, of July 1862.

It seems that there was an operation to cut a canal across the pennisular of land that formed the Bend of the Mississippi River that the batteries at Vicksburg controlled. By cutting a channel across this now stretch of land the Union boats would would be able to bypass the Vicksburg guns all together.

This would have prompted the Federals to deploy pickets and scouts in the direcion of Monroe to provide security. I am sure this would have raise an alarm in Monroe.