The History of American Currency

1776
The First $2 Note
The first $2 notes are Continentals and are nine days older than America. On June 25, 1776, the Continental Congress authorizes issuance of the $2 denominations in “bills of credit” for the defense of America.
1861
Demand Notes
In order to finance the Civil War, Congress authorizes the U.S. Department of the Treasury to issue non-interest-bearing Demand Notes. These notes earn the nickname “greenbacks” because of their color. All U.S. currency issued since 1861 remains valid and redeemable at full face value.
1862
United States Notes
Congress authorizes a new class of currency, known as “United States notes,” or “Legal Tender notes.” These notes are characterized by a red seal and serial number. They continue to circulate until 1971.  
1862
The Foundation of Modern Design
By 1862, the Demand Notes incorporate fine-line engraving, intricate geometric lathe work patterns, a U.S. Department of the Treasury seal, and engraved signatures to aid in counterfeit deterrence. To this day, U.S. currency continues to add features to deter counterfeiting.
1863
A National Banking System
Congress establishes a national banking system and authorizes the U.S. Department of the Treasury to oversee the issuance of National Banknotes. This system sets Federal guidelines for chartering and regulating "national" banks and authorizes those banks to issue national currency secured by the purchase of United States bonds.
1869
Centralized Printing of United States Notes
The Bureau of Engraving and Printing begins engraving and printing the faces and seals of U.S. banknotes. Before this, U.S. banknotes were produced by private banknote companies and then sent to the Bureau of Engraving and Printing for sealing, trimming, and cutting.
1889
Names Added to Portraits
Legislation mandates that all banknotes and other securities containing portraits include the name of the individual below the portrait. This is why you see names below the portraits on banknotes to this day.
1913
Federal Reserve Act
The Federal Reserve Act of 1913 establishes the Federal Reserve as the nation’s central bank and provides for a national banking system that is more responsive to the fluctuating financial needs of the country. The Federal Reserve Board issues new currency called Federal Reserve notes.
1929
Standardization of Design
The appearance of U.S. banknotes changes greatly in 1929. In an effort to lower manufacturing costs, all Federal Reserve notes are made about 30 percent smaller—measuring 6.14 x 2.61 inches, rather than 7.375 x 3.125 inches. In addition, standardized designs are instituted for each denomination, decreasing the number of designs in circulation and making it easier for the public to distinguish between genuine and counterfeit notes.
1957
"In God We Trust"
Following a 1955 law requiring “In God We Trust” on all currency, the motto first appears on banknotes on series 1957 $1 silver certificates, then on 1963 series Federal Reserve notes.
1971
United States Notes Discontinued
Because United States notes no longer served any function not already adequately met by Federal Reserve notes, their issuance was discontinued and, beginning in 1971, no new United States notes were placed into circulation.
1990
Security Thread and Microprinting
A security thread and microprinting are introduced in Federal Reserve notes to deter counterfeiting by copiers and printers. The features first appear in Series 1990 $100 notes. By Series 1993, the features appeared on all denominations except $1 and $2 notes.
1996
Currency Redesign
In the first significant design change since the 1920s, U.S. currency is redesigned to incorporate a series of new counterfeit deterrents. Issuance of the new banknotes begins with the $100 note in 1996, followed by the $50 note in 1997, the $20 note in 1998, and the $10 and $5 notes in 2000.
2003
The Redesigned $20 Note
The new-design $20 note features subtle background colors of green and peach. The $20 note includes an embedded security thread that glows green when illuminated by UV light. When held to light, a portrait watermark of President Jackson is visible from both sides of the note. In addition, the note includes a color-shifting numeral 20 in the lower right corner of the note.
2004
The Redesigned $50 Note
The currency redesigns continue with the $50 note, which features subtle background colors of blue and red. The $50 note includes an embedded security thread that glows yellow when illuminated by UV light. When held to light, a portrait watermark of President Grant is visible from both sides of the note. In addition, the note includes a color-shifting numeral 50 in the lower right corner of the note.
2006
The Redesigned $10 Note
The new-design $10 note features subtle background colors of orange, yellow, and red. The $10 note includes an embedded security thread that glows orange when illuminated by UV light. When held to light, a portrait watermark of Treasury Secretary Alexander Hamilton is visible from both sides of the note. In addition, the note includes a color-shifting numeral 10 in the lower right corner of the note.
2008
The Redesigned $5 Note
The new-design $5 note features subtle background colors of light purple and gray. The $5 note includes an embedded security thread that glows blue when illuminated by UV light. Two watermarks are featured in the $5 note, which are visible from both sides of the note when held to light. A vertical pattern of three numeral 5s is situated to the left of the portrait and a large numeral 5 is located in the blank space to the right of the portrait.
2013
The Redesigned $100 Note
In its first redesign since 1996, the new-design $100 note features additional security features including a 3-D Security Ribbon and color-shifting Bell in the Inkwell. The new-design $100 note also includes a portrait watermark of Benjamin Franklin that is visible from both sides of the note when held to light.