With the passage of the National Security Act in 1947, a concentrated effort was begun to consolidate the functions of the U.S. military services wherever possible. One area that seemed appropriate for merger was the several units that were providing ocean transportation for the services.
Gibson, Andrew E. and Calhoun, William M.
"Barely in Time: The Successful Struggle to Create the Transportation Command,"
Naval War College Review: Vol. 43
, Article 6.
Available at: http://digital-commons.usnwc.edu/nwc-review/vol43/iss4/6