[1][2] It consisted of the forts, controlled underwater minefields, and other coastal defenses of a particular harbor or river.
These commands originated as Artillery Districts, to control groups of forts constructed under the Endicott Program beginning in 1895.
[4][5] Mine planter vessels were also attached to these commands to plant and maintain controlled minefields.
Some of the disarmed commands were rearmed in World War II with "Panama mounts", circular concrete platforms for towed 155 mm guns.
[8][9] After World War II all of these commands were disarmed within a few years, and they and the Coast Artillery Corps were disestablished in 1950.