Firing that stops the work
The Federals opened on Fort Sumter from Gadberry Hill at 11.40 and shelled Fort Johnson so vigorously through the afternoon that the working party — enslaved laborers, impressed for the defenses — had to be withdrawn. Work resumed at dusk and ran through the night to make up the lost time. Of 68 shots at Fort Sumter, 31 struck inside; one man was slightly wounded.
Journal of Operations in Charleston Harbor, OR I, 28, Pt. 1