Even during the Civil War, the United States Navy's ships brought ashore soldiers, sailors, and Marines to capture coastal forts.
General Robert E. Lee, the Confederate Army commander, declared: The victory over Spain in the Spanish–American War had greatly enabled the expansion of the United States.
By the time the Treaty of Paris was ratified in 1898 the United States had annexed the Philippines in the western Pacific to influence foreign relations in China and Korea; primarily through the presence of the Asiatic Squadron.
[4] Around this time, the General Board developed some potential war plans for possible events that may be measured if such attacks were to be aimed for the continental east coast, the Antilles of the Caribbean, or the Panama Canal.
If such an attack was initiated by the Japanese, a system of Pacific naval bases were needed to be built, in order to put War Plan Orange into effect.
[7] The sum of it all, the Navy's war planning after 1900 assumed that maritime attacks on the United States and its interests were possible in both the Pacific and the Caribbean, and given the thousands of miles the fleet would have to steam to provide security to the outermost bases of Guam, the Philippines, or of the similar.
[2] On the outset of the Spanish–American War, the Marines stormed the beaches of Cuba and captured Guantanamo Bay while the United States Army landed at Santiago.
Throughout the Pacific campaign during World War II, the United States Army and Marine Corps trained the new graduated recruits in joint-amphibious operations.
The number of amphibious troops in the United States was inadequate and the Marine Corps was undermanned due to shortages in the Department of Navy's budget.