After over a century of squabbling, the U.S. Army, under pressure from the Department of Defense, is surrendering the last of its fleet to the U.S. Navy. The army still has 119 ships, manned by 2,300 soldiers and civilians. While six of them are large amphibious landing ships, most are tugboats and barges for work in or near ports.
The army isn't new to owning its own transports. Back during World War II, the U.S. Army actually had a larger fleet (but only 1,225 seagoing ships), than the U.S. Navy, but one that was almost entirely support vessels. The navy had a larger tonnage of ships, about 12 million tons, compared to about 7 million for the army. Moreover, the navy had 6,228 seagoing ships, about half of them warships. The rest were support ships.
The big change after World War II was the scrapping of most of the amphibious ships (including most of the 140,000 small amphibious craft the army and navy used), and support ships. Increasingly, the navy used commercial shipping to move a lot of supplies around, and had a lot fewer support ships in general. This was largely because during World War II, the navy had maintained a huge fleet of warships (over a thousand) in the Pacific, almost entirely without ports for replenishing. This was an unprecedented operation, the likes of which will probably never be seen again. The navy also took over most of the army support ships after World War II.
The army and navy have been feuding over the size of the army fleet ever since the mid 19th century, when the army built a large fleet to support its many amphibious operations. The army believes it has a need for some of its own ships, mainly for operating ports and amphibious beachheads. The army likes to remind the navy, and the marines, that soldiers carried out more amphibious operations in the last century than the marines have, and are still ready to fight their way across a defended beach. But in the current state of the economy, the Department of Defense wants the army to finally give up all its ships, and it looks like that is now going to happen. Not in the name of military necessity, but to balance the budget.