What is the value of a US bill with a red seal?

Answer 1

Red-seal bills were printed in many denominations and for more than a century, so a date and denomination are needed in order to estimate a value.

Prior to 1928 many different types of US paper money were printed with red seals and serial numbers. That year the Treasury adopted standard colors to distinguish the four types of bills that were then in circulation. A red seal and serial numbers identify a bill as a United States Note, a banknote issued directly by the Federal government instead of through a bank.

US Notes were printed for for about a century but were eliminated in the 1960s in favor of issuing all currency as Federal Reserve Notes.