When Johnston evacuated the Peninsula, he also abandoned a large number of Confederate forts, water batteries, and defensive lines. The Rebels had expended a great deal of labor for many months perfecting several kinds of earthworks on the Peninsula and along the banks of the James River. Only the Warwick Line proved its mettle in a direct confrontation with McClellan's army. The engineering skill, time, and labor invested in most of the others were ultimately wasted.
The lower James was defended by numerous works. The Confederates fortified six major positions: Fort Boykin at Day's Point, Fort Huger at Harden's Bluff, Mulberry Island (the western anchor of the Warwick Line), Jamestown Island, Fort Powhatan (near the mouth of the Chickahominy), and Drewry's Bluff. The works at Jamestown Island were the most extensive, while the defenses at Drewry's Bluff were the most important. The latter place was the last river defense site capable of preventing Yankee gunboats from steaming to Richmond.1
On Jamestown Island, as at Yorktown, the Rebels were digging in hallowed ground, the site of England's first permanent colony in North America. A small island off the mainland, on the north side of the James River about fifty miles downstream from Richmond, it was also the site of several colonial fortifications. The first was merely an abatis shaped like a half-moon, which was replaced by an earthen fort in June 1607. It was triangular in shape, mounted artillery, and enclosed one acre. The wooden components of James Fort burned in January 1608 and were rebuilt later that year. Capt. John Smith soon after enlarged the fort into a pentagonal shape. A blockhouse was added in 1609 to guard the isthmus that connected the colonists to the mainland. This isthmus eventually eroded, and the settlement was left on an island.
Two other colonial fortifications were built to protect the colony. About 1663 a detached work with four sides was constructed east of the settlement but was dismantled within twenty years. A second fort, built in the 1670s,