What does a brown seal on US currency mean?

Answer 1

Brown seals have been used on several different types of US paper currency:

Up till 1928 there were no standards for seal colors. Brown seals appeared on United States Notes, US Treasury Notes, silver certificates, and/or gold certificates depending on the date of issue, denomination, and presumably the opinions of the officials who authorized the bills' production.

Seal colors were standardized that year as part of a major currency redesign*. Brown was assigned to National Currency Notes, a form of paper money that was issued by federally-chartered banks rather than by the Federal Reserve or directly by the Treasury. The use of brown ink was suspended only a few years later when the government discontinued National Currency Notes in an effort to stabilize the monetary system during the Depression.

Brown ink reappeared following the attack on Pearl Harbor in December 1941. Special $1, $5, and $10 silver certificates were printed for use in Hawaii. In addition to brown seals and serial numbers these bills also carried the word HAWAII in large letters. The goal was to limit damage to the money supply if the islands were invaded and large amounts of currency were captured. Bills with brown seals could be declared worthless without affecting the validity of standard-color bills on the mainland.

Since that time, no other US currency has used brown seals.

(*) Other colorsOther colors adopted as part of the 1928 redesign were

• Blue - silver certificates (discontinued with the 1957-B series of $1 bills)
• Gold - gold certificates (discontinued across all series in 1933)
• Red - United States Notes (discontinued with the 1966-A series of $100 bills)
• Green - Federal Reserve Notes, the only color still in use.