| Old Seal — Prior to Series 1996, each Federal Reserve Note bears a regional seal at the left of the portrait. This seal, printed in black, bears the name of the issuing Federal Reserve Bank and the letter designating the Federal Reserve district in which that bank is located. In 1928, the number of the Federal Reserve district was printed. |
On subsequent 1928-Series until 1950-Series, the letter representing the Federal Reserve District was printed in a large circular seal. The change from a numeric designation to a letter designation was made because the numeric designation was often confused for the denomination of the note. |
On notes of the 1950 series and later, the black Federal Reserve regional seal is smaller than earlier designs and is surrounded by sharp points. |
New Seal —Starting with the 1996 series Federal Reserve notes, a new universal seal represents the entire Federal Reserve system. A letter and number below the upper left serial number identifies the issuing Federal Reserve Bank. |
| 1928 $100 Federal Reserve Note |
1928A $100 Federal Reserve Note |
1950C $100 Federal Reserve Note |
2006 $100 Federal Reserve Note —- Under the serial number is "B2" representing the Federal Reserve Bank of New York City. |
