Harbor Defenses of the United States of America

Fort Delaware State Park, Delaware City, DE

Fort Delaware State Park, Delaware City, DE

It has been a basic military policy of most nations to secure their borders against possible attack through the construction of defensive fortifications. Except for an attack from Canada or Mexico, all American adversaries would have to come from overseas. The United States sought security against an attack through fortification of her maritime frontiers. Fortifications were viewed both by the U.S. Congress and the American public as a way to avoid foreign entanglements and war, and to avoid the dangers of a standing army. This thinking had a strong influence on American national defense policy and during certain periods fortification construction was nearly a substitute for any other form of military policy. Seacoast fortification was attractive to the United States government. Few military principles were as enduring as the superiority of guns ashore over those afloat. The United States had a long shoreline, a weak navy (at least until the early 20th century), and a concern about foreign attack.

Golden Gate National Recreation Area, San Francisco, CA

Golden Gate National Recreation Area, San Francisco, CA

The use of seacoast fortifications also complied with another long standing American military tradition – reliance on militia forces. Seacoast fortifications, once constructed of masonry or concrete, could be maintained by a caretaker force.

The American government invested large sums of money in several major peacetime coastal defense construction programs: the “First System” (1794-1800), the “Second System” (1804-1812), the “Third System” (1816-1867), construction after the Civil War (1870-1875), the “early modern programs” (Also known as the “Endicott Board”, “Taft Board”, and “post-WWI” programs) (1890-1920s), and the Harbor Defense Modernization Programs of WW2 (1940-1945). Manning the coastal defenses was a major mission of the U.S. Army for over 150 years. After 1907, the army had a branch of service that was specifically dedicated to operate these complicated weapons: the Coast Artillery Corps (C.A.C.).

Fort Columbia State Park, Chinook, WA

Fort Columbia State Park, Chinook, WA

American naval dominance made U.S. coast artillery obsolete by the end of WW2. The C.A.C. increasingly concentrated on the antiaircraft role, and by 1950 the U.S. Army had dismantled all its fixed harbor defenses.

Click Links below to learn more about the phases of American Seacoast Defense Construction

First, Second & Third Systems (1794-1860)

Civil War & Post-Civil War (1861-1875)

Early Modern Programs (Endicott & Taft, 1886-1917)

Post-WWI Period (1917-1940)

WWII Programs (1940-1950)

US Coast Defense Sites (1945-Present)