On april 2, 1862, the first greenback left the u. s. treasury, marking the start of a new era in the american monetary system.

at the start of the civil war, the u. s. didn't have a national paper currency. instead, the money supply consisted of u. s. coins and a collection of paper notes issued by private banks. technically, the federal government began issuing its own paper currency in 1861. that year, the lincoln administration issued $60 million in demand notes, a variant of a treasury note that was redeemable "on demand" for gold coins at the treasury or any sub-treasury.

these notes were overshadowed in 1862 by the issue of $150 million in a new fiat currency officially known as united states notes and popularly known as greenbacks or legal tenders. by the end of the war, close to $450 million worth of greenbacks were in circulation.