Confederate forces built five earthworks to defend the Mulberry Island and James River flank of Major General John Bankhead Magruder’s 2nd Peninsula Defensive Line, stretching from Lee’s Mill on the Warwick River to Skiffes Creek to block any Federal flanking movement by way of Mulberry Island or Skiffes Creek. Before the emergence of the ironclad ram CSS Virginia (Merrimack), Magruder worried that his small force could not effectively fortify its James River flank, writing General Robert E. Lee in early 1862 that he could “only hope that Yorktown and Mulberry Island will be made impregnable, else the Peninsula and perhaps Virginia overrun.” Despite shortages of troops and artillery, his men, supported by as many as 600 to 1,000 slaves a day, constructed extensive defenses throughout Mulberry Island, including entrenchments at Land’s End and Brick House Creek, batteries at Mulberry Island Point, redoubts near Skiffes Creek, and Fort Crawford, the largest earthwork in the 2nd Defensive Line. Fort Crawford covered 8 acres, had inner walls almost 20 feet high, and mounted 8 heavy cannon. Magruder believed the Mulberry Island fortifications could withstand a month-long siege, but they did not play a major role in the Warwick River–Yorktown Siege because CSS Virginia (Merrimack) was able to block the James River to Union use. The Mulberry Island and Skiffes Creek fortifications were abandoned on May 3, 1862, when the Confederate army began its retreat toward Richmond.
