U.S. currency comes in many different denominations, but the one-dollar bill in used most frequently, according to the U.S. Secret Service. While paper money has been traded in the United States for hundreds of years, the current system first was designed during the Civil War by Abraham Lincoln's Secretary of Treasury, Salmon P. Chase.

"Greenbacks" Fund Civil War

After a political career as a U.S. senator and governor for Ohio, Salmon P. Chase became Abraham Lincoln's Secretary of Treasury in 1861. With the Civil War underway, Chase established a new banking system and issued paper currency called Demand Notes or "greenbacks" because of their color. The new monetary system provided a means to fund the Civil War and became the foundation for today's currency. By 1862, printing of the new money included intricate patterns, the treasury seal and engraved signatures in an effort to thwart counterfeiting.

Chase Gets on the Bill

The first Demand Notes issued in 1861 were the $10 denomination and featured President Lincoln. Eager to "be among the people," Chase made sure his picture was on the end of the $1 bill when it was first issued in 1862, according to curator Richard Cote in his article "Historic Photograph of Salmon P. Chase Donated to the Treasury." Washington photographer Henry Ulke captured Chase's likeness to be engraved.

Chase's Legacy

In 1863, Chase orchestrated the National Banking Act. By 1864, Chase had resigned from his position as Secretary of Treasury and was appointed as Chief Justice of the U.S. Supreme Court. As Chief Justice, Chase oversaw cases related to Reconstruction following the Civil War, and the impeachment of President Andrew Johnson. In 1877, banker John Thompson established Chase National Bank, honoring Chase posthumously, according to Srinivas B. Prasa in the publication "The Metamorphosis of City and Chase as Multinational Banks."

The Modern Dollar Bill

The modern dollar bill has gone through many changes since it was first issued. The images and words and their placement have been altered, as well as the addition of watermarks and improvement of material to make counterfeiting more difficult. While other denominations such as $5 and $10 have undergone major redesigns since the 1990s.