To replace the massive shipping losses in the Atlantic, the U.S. began mass-producing 'Liberty Ships.' These cargo vessels were built using a revolutionary modular assembly process. While the first ship took 244 days to build, the 'SS Robert E. Peary' was famously assembled in just 4 days, 15 hours, and 29 minutes. Though designed to be cheap and 'expendable' with a lifespan of only five years, their sheer volume—over 2,700 were built—overwhelmed the German U-boats' ability to sink them, ensuring the 'Arsenal of Democracy' could reach the battlefield.