Several boards have been appointed by US presidents or Congress to evaluate the US defensive fortifications, primarily coastal defenses near strategically important harbors on the US shores, its territories, and its protectorates.
In 1885 US President Grover Cleveland appointed a joint Army, Navy and civilian board, headed by Secretary of War William Crowninshield Endicott, known as the Board of Fortifications (now usually referred to simply as the Endicott Board). The findings of the Board in its 1886 report illustrated a grim picture of neglect of America's coast defenses and recommended a massive $127 million construction program for a series of new forts with breech-loading cannons, mortars, floating batteries, and submarine mines for some 29 locations on the US coast. Coast Artillery fortifications built between 1885 and 1905 are often referred to as Endicott Period fortifications.
Prior efforts at harbor defense construction had ceased in the 1870s. 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. In 1883, the Navy had begun a new construction program with an emphasis on offensive rather than defensive warships, and many foreign powers were building more heavily armored warships with larger guns. These factors combined to create a need for improved coastal defense systems.
The Endicott Era Defenses were constructed, in large part, during the years of 1890-1910 and some remained in use until 1945. 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. Masonry walls shrouding hordes of smooth-bore cannon could no longer serve as a primary coastal defense mechanism, thus the Endicott Era Defenses were born.
Endicott Era Forts were constructed with concrete walls that concealed large, breech-loading rifled cannons mounted on "disappearing carriages". These disappearing carriages allowed the new, rifled cannons to be raised above the walls, aimed, and fired, and then quickly moved back underneath the walls, becoming invisible from the sea. 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. These larger guns were complemented by a variety of other ordnance best explained by describing the armament of Fort Hancock, one of the vanguards of New York's Southern Harbor, part of which was the prototype by which all other Endicott Era forts were constructed.