Eastern Sea Frontier

The Eastern Sea Frontier (EASTSEAFRON) was a United States Navy operational command during World War II, that was responsible for the coastal waters from Canada to Jacksonville, Florida, extending out for a nominal distance of two hundred miles. The Commander was designated Commander, Eastern Sea Frontier (COMEASTSEAFRON).

The commander of a Sea Frontier had control and responsibility for convoys within its defined area, had its own vessels for convoy use or other uses as determined by the commander, and worked closely with the U.S. Army Air Force in the defense of the frontier. Usually, offices of the U.S. Navy and U.S. Army Air Force officers assigned to the frontier, had their offices side by side in order to create effective two-way communications and expedited reaction to reports of enemy presence. In addition to providing escorts for convoys within its frontier, the frontier was responsible for sea-air rescue, harbor defense, shipping lane patrol, minesweeping, and air operations.

Eastern Sea Frontier's commander also served as commander of the Atlantic Reserve Fleet as of 1937-38.

Eastern Sea Frontier's headquarters were located at 90 Church Street in Lower Manhattan. The commander of the Eastern Sea Frontier, until the closing months of 1943, was Vice Admiral Adolphus Andrews whose operational orders could only be appealed to Admiral Ernest King. This frontier was the "parent" of all frontiers, and its authority extended beyond its own frontier.

Vice Admiral John S. McCain, Jr. served as Commander, Eastern Sea Frontier, 1965-67, and he was relieved by Admiral Andrew McBurney Jackson, who retired in 1969.