The South Atlantic Blockading Squadron division commanded by Union Captain George Balch set out to capture Confederate steamboats on the St. Johns River. Seized at Lake Monroe on March 14, 1864, was the "Hattie Brock", named for the captain's daughter, and loaded with 150 bales of cotton for export to help finance the rebel cause. It was towed to Brock's wharf to load wood fuel. From the veranda of The Brock House, the "New York Tribune" would report, Miss Brock expressed grief and indignation at the capture of her namesake by the Yankees. The marines were reportedly glad to get away as soon as their boats were supplied. They took with them from Enterprise two black males, probably slaves, and three black females, as well as 2,000 pounds of sugar from a refinery. They demolished the mill, located about farther downriver on the east side of DeBary Creek.