Your United States Note is worth $20 to $50 retail, depending on how worn it is. 1928 was the last time $1 bills were printed as red-seal United States Notes.
1928 $50 bills were issued as gold certificates and as Federal Reserve Notes but they're not the same. Please check the wording across your bill's top front as well as its seal color*; then see one of the following questions: "What is the value of a 1928 US 50 dollar Federal Reserve Note?""What is the value of a 1928 US 50 dollar gold certificate?"* Gold certificates have gold seals and FRNs have green seals.
"A" is the highest series letter for 1928 $50 Federal Reserve Notes. "K" is most likely the Federal Reserve District letter. The series letter, if any, on US bills is next to the date. Please see the question "What is the value of a 1928 US 50 dollar Federal Reserve Note?" for more information on values.
To determine the exact value of a 1928 US dollar coin, a couple different factors would need to be taken into consideration. Most important factor being, the condition of the coin.
the serial number does not match the series
Please check your bill again. There were no 1926 US bills; the date is most likely 1928.If so, there's more information the at question "What is the value of a 1928 G US 2 dollar bill?".
The green seal indicates that it's a Federal Reserve Note. Please see the question "What is the value of a 1928 US 5 dollar Federal Reserve Note?" for more information.
Your bill is called a United States Note rather than a promissory note. There were eight different subseries within the 1928 series date; please see the question "What is the value of a 1928 US 2 dollar bill?" for specific information about values.
A denomination is needed. Please look for questions in the form "What is the value of a 1928 A US [denomination] dollar Federal Reserve Note?" for specific information.
The green seal indicates that your bill is a Federal Reserve Note. Please see "What is the value of a 1928 D US 5 dollar Federal Reserve note?" for more information.
1928 $50 bills weren't issued as silver certificates. Please check the wording across your bill's top front; then see one of the following questions:"What is the value of a 1928 US 50 dollar Federal Reserve Note?""What is the value of a 1928 US 50 dollar gold certificate?"
Not every old bill is automatically a certificate so it's important to check carefully. If it has a gold seal and says "Gold Certificate", see the question "What is the value of a 1928 US 10 dollar gold certificate?" for values. If it has a green seal and says "Federal Reserve Note", it's not a certificate, it's a Federal Reserve Note. See the question "What is the value of a 1928 US 10 dollar Federal Reserve Note?" for values.
1928-series $100 bills weren't issued as silver certificates, only gold certificates and Federal Reserve Notes. Please look at the bill's front to determine which you have; then check one of the following: "What is the value of a 1928 US 100 dollar Federal Reserve Note?" "What is the value of a 1928 US 100 dollar gold certificate?"
Could you check your bill again? A red seal would indicate that your bill is a United States Note; the first $2 FRNs were dated 1976 and have green seals. If you have a US Note, there's more information at the question "What is the value of a 1928 US 2 dollar bill?"
1928 $50 bills were issued as gold certificates and as Federal Reserve Notes but they're not the same. Please check the wording across your bill's top front as well as its seal color*; then see one of the following questions: "What is the value of a 1928 US 50 dollar Federal Reserve Note?""What is the value of a 1928 US 50 dollar gold certificate?"* Gold certificates have gold seals and FRNs have green seals.
The green seal indicates that your bill is a Federal Reserve Note. All 1928 B $20 bills were printed as FRNs. Please see the question "What is the value of a 1928 B US 20 dollar bill?" for more information.
In worn condition, about $5. In better shape, around $10.
Please don't assume that every old bill has to be a silver certificate. 1928 $10 bills were issued as gold certificates with gold seals and as Federal Reserve Notes, with the familiar green seal and the words "Federal Reserve Note" across the top.Please check the bill's seal color and wording across your bill's top front; then see one of the following questions:"What is the value of a 1928 US 10 dollar Federal Reserve Note?""What is the value of a 1928 US 10 dollar gold certificate?"