Link: http://www.npr.org/blogs/money/2012/12/07/166747693/episode-421-the-birth-of-the-dollar-bill
Summary: At one point in U.S. history there was close to 8,000 different types of currency circulating. The Civil War became a bottleneck and forced innovation, thus creating one unified currency.
Original Air Date: December 7, 2012
Length: 10 minutes 37 seconds