Seacoast defense was a major concern for the United States from its independence through World War II. Before airplanes, many of America's enemies could only reach it from the sea, making coastal fort
The outer works of Fort McHenry in Baltimore harbor, although built in the 1860s, are broadly similar to early First and Second System forts built before the War of 1812, with low earthworks, although mounting much larger cannon and reinforced with masonry. The cannon are 8-inch converted rifles (lined down from 10-inch Rodman guns) and a 15-inch Rodman gun, typical of the post-Civil War era.
The Statue of Liberty is built on top of Fort Wood of the Second System
50-pounder Model 1811 Columbiad (7.25-inch or 184 mm bore) and center-pivot mounting designed by George Bomford as an experimental coastal defense gun. This gun was built in 1811 as a component of the Second System. Photographed in Clear Lake, Wisconsin.
Fort Point – San Francisco – example of a mid-1800s Third System fort
Fort Pulaski National Monument is located on Cockspur Island between Savannah and Tybee Island, Georgia. It preserves Fort Pulaski, the place where the Union Army successfully tested rifled cannons in
Seacoast defense in the United States
…Charleston, South Carolina: Fort Sumter; Savannah, Georgia: Fort Pulaski; St. Marys River, Florida: Fort Clinch…
Ft Pulaski Inside
Fort Pulaski was used as Confederate prison camp from 1861 to 1862.
Col. Charles H. Olmstead
CSS Livingston (misspelled Livingstone), Ida, Beauregard and other ships at Savannah River, near Fort Pulaski; under flag-of-truce.