Cape Charles guards the northern flank of Chesapeake Bay's mouth, mirroring Cape Henry across the water to the south. The Army knew the geometry: any enemy attempting to seize Hampton Roads — the strategically vital harbor that holds Norfolk, Newport News, and the entire Navy's Atlantic anchorage — had to pass between these two capes. In 1941, with the United States edging toward war, the Army established Fort Winslow here. Confusion with nearby Fort Eustis prompted a quick rename to Fort Custis, then Fort John Custis in October 1942, after John Parke Custis — Martha Washington's son, who died at Yorktown in 1781 — whose family had long held land on Virginia's Eastern Shore. The fort's job was simple in concept and enormous in execution: defend Chesapeake Bay with guns big enough to sink anything that tried to enter.

Battery Winslow was the centerpiece — two casemated 16-inch guns lifted from decommissioned battleships, set into thick concrete bunkers, capable of throwing 2,700-pound shells over twenty miles. With identical batteries at Fort Story across the bay, they created an interlocking field of fire across the entire mouth of the Chesapeake. A second 16-inch battery was planned but never built. On Fisherman Island, just offshore, four 155mm guns sat on circular concrete 'Panama mounts' that let them rotate to track moving targets. Ten fire control towers rose from islands and points along the Eastern Shore, with observers triangulating ranges to coordinate the guns. Three of those towers still stand on Smith Island. One survives near Kiptopeke. They look like concrete grain silos with slit windows.

The 16-inch guns never fired at an enemy ship. By 1948 they were gone, scrapped or relocated. The Coast Artillery itself was disbanded. The land sat quiet for two years until the Korean War accelerated a Cold War priority: radar coverage. The Air Force chose Fort Custis for one of thirteen rushed-into-service radar stations — the so-called Lashup network — and the 771st Aircraft Control and Warning Squadron activated in November 1950. AN/CPS-5 and CPS-4 radars went up where artillery spotters had once watched the bay. The base was redesignated Cape Charles Air Force Station in December 1953. A small airfield was carved out of the pines for resupply, since the southern Delmarva is hard to reach by road.

In 1959 Cape Charles AFS joined SAGE — the Semi-Automatic Ground Environment — the massive computerized air defense network that fed radar data through vacuum-tube IBM mainframes to direct interceptor aircraft against Soviet bombers. Cape Charles's data went to DC-04 at Fort Lee AFS in central Virginia. The squadron added FPS-6 height-finders, an FPS-7 long-range radar, and an FPS-26A. Three unmanned gap-filler radar sites — at Temperanceville, Bethany Beach, and Elizabeth City — extended the coverage. In 1963 the FAA joined as a co-user. SAGE itself became obsolete by the 1980s; cheaper, more flexible systems replaced it. Cape Charles AFS closed on June 1, 1981, when the 771st Radar Squadron (SAGE) was deactivated, and its mission moved to the Joint Surveillance System at NAS Oceana.

The buildings came down. The runway pavement broke up. In 1984 the site became part of the Eastern Shore of Virginia National Wildlife Refuge, 1,123 acres of maritime forest, freshwater ponds, and salt marsh now critical to migratory birds — peregrine falcons, monarchs, and warblers funnel down the peninsula every fall. Fisherman Island National Wildlife Refuge next door is closed to the public, a sanctuary for nesting brown pelicans and royal terns. A single fire control tower from Fort John Custis still stands near where the runway used to be. The 16-inch gun sits at Battery Winslow's old footprint — the only artifact a casual visitor will ever see of what the army once protected and the air force once watched from here.