The 1928 series of United States Note, the first small-size banknotes issued in the United States. The $2 and $5 bills in this series, which replaced the large-sized notes that had been used since the Civil War, were introduced in 1929, though $1 notes were issued in 1933 in response to the Great Depression. The obverses of these bills were similar to contemporary Federal Reserve Notes, but can be readily differentiated by their red (not green) U.S. Treasury Seals and serial numbers.
This set of three images from the National Numismatic Collection at the National Museum of American History show the first $1, $2, and $5 notes printed. Each has the serial number A00000001A.
See another banknote: $1 – $2Banknote: Bureau of Engraving and Printing (image courtesy of the National Numismatic Collection, National Museum of American History)