16 1/2 x 7 1/8 in. paper sheet, with creases along folds, soiling, and chipping to edges, corners, and crease intersections. Inscribed in ink across upper edge, "The Five Blockaded Harbours of the Confederate States of N. America" and below sketch, "No. 1 Charlestown Harbour."

Sketch features a panoramic view of the harbor from a vantage point to the east of Fort Sumter (most likely southeast, perhaps from a watercraft), showing Fort Johnson on James Island to the left, Fort Sumter at center, and Fort Moultrie on Sullivan's Island to the right. The artist also includes the city of Charleston with St. Michael's spire featuring prominently in the skyline. An inscribed key beneath the caption identifies important locations, corresponding with numbers above and below certain structures and landmarks in the drawing. The artist even includes a marker, "3," for the "Bluff for entering the Bar as far as the inner bouy [sic]."

The only color used in the entire sketch is the slightest bit of red ink, used to enhance the flags flying over the forts featured in the illustration.