The first ‘Liberty Ship’, the Patrick Henry, was launched in Baltimore on 27 September 1941. Thousands of these 10,000-ton cargo vessels would be built in the USA before the war finally ended in 1945. By that time, the industrial capacity of the Unites States was 25 times what it had been in 1939.

The early Liberty Ships took 200 days to build. (Britain had originally placed the order for such ships in 1940). It was essential that Britain acquire cargo ships and send them into the Atlantic at a faster rate than the German U-boats were sinking them.

Improved design and streamlined production reduced the time to build a Liberty Ship to as little as 24 days and (by 1944) to an amazing 17 days . The key was to employ welding instead of riveting.

The USA would become the only country to enter WWII and experience a rise in standard of living. Unemployment, which had been several million before the war, would drop to zero.