Source: adapted from B.J. Cudahy (2006) Box Boats: How Container Ships Changed the World, New York: Fordham University Press. p. 8.
The United States Maritime Commission was established by the Merchant Marine Act of 1936 to devise a merchant shipbuilding program to equip the United States with a fleet of 500 modern cargo ships. The goal was to replace the cargo vessels built in the wake of World War I (of a capacity of about 8,500 tons) with new ship designs that were faster, of greater capacity, and more energy-efficient. Several classes of ships were designed based upon the input from the industry and the US Navy with the C (Cargo) and T (Tanker) classes of particular importance to maritime shipping.
The Liberty Ships (Emergency Cargo class 2), with 2,710 laid up as part of a crash program, became the most important class of cargo ships ever to be mass-produced. They could be built in about 60 days and played an important role in ferrying supplies and troops across the Atlantic and the Pacific.
An important consequence of these shipbuilding programs was the availability after WWII of a large number of surplus cargo ships that were purchased by several maritime shipping companies in the United States and abroad (e.g. Greece). It also permitted the beginning of containerization since the first containership launched in 1956 was a converted T2 tanker (Ideal X).