Board of Fortifications

Since that time the design and construction of heavy ordnance had advanced rapidly, including the development of superior breech-loading and longer-range cannon, making U.S. harbor defenses obsolete.

Endicott Era Forts ushered the transition from mortar to concrete as a building material in response to the massive technological discoveries in arms and ordnance brought on by the American Civil War.

Endicott Era Forts were constructed with concrete walls that concealed large, breech-loading rifled cannons mounted on "disappearing carriages".

The fact that these cannons were "breech loading" is also not to be overlooked as a significant technological advancement, as it allowed for a much more rapid, accurate, and safe manipulation of artillery by its crew.

This became even more important as warships of the era (such as the Spanish battleship Pelayo) were armored with steel plates, increasing the necessity of accurate, sustained fire in anti-ship warfare.

[citation needed] An easily overlooked aspect of the Endicott Era Defenses, especially with the necessary highlighting of the breech-loading rifled artillery mounted on disappearing carriages, are the mortars.

The reason is because the mortars were: 1) voluminous 2) before the establishment of the Coast Artillery Corps in 1907 (see below) they operated in the Abbot-Quad design, which very nicely complemented the capabilities of the larger, rifled guns.

Of the Endicott Era Defenses armaments, the mortars exceeded all but the 12" M1888 (disappearing carriage) guns in range and, although pursuant to the Abbot-Quad design they were not intended to operate as such, they did have a 360 degree field of fire providing great versatility.

Most of the changes recommended by the Taft Board were technical, such as adding more searchlights, electrification (lighting, communications, and projectile handling), and more sophisticated optical aiming techniques.

By the time of the First World War, many of the Endicott and Taft era forts had become obsolete due to the increased range and accuracy of naval weaponry and the advent of aircraft.

Several Taft era fortifications in the Philippines were attacked and captured by Imperial Japanese forces within a few months of the U.S. entry into World War II.

The following table of Endicott Era carriages is summarized from American Seacoast Defenses, edited by Mark Berhow, with pages referenced from the rows.