Dollar bills are common today, but before 1862, gold and silver were the main way to pay. That worked until the Civil War (1861-1865), when the U.S. government’s gold and silver reserves ran low.
In response, Congress passed the Legal Tender Act in February 1862, authorizing the creation of U.S. notes, the country’s first widely circulated paper currency. The government printed $150 million worth of the money, also known as legal tender notes or greenbacks. The first set ranged in value from $5 to $1,000.
Although the currency was meant to be a temporary way to pay troops, the notes remained in circulation for a century.
The photograph above shows the earliest version, approved 160 years ago this month.