There was only one series of 1976 $2 bills printed, so there are no series letters.
Most likely you're looking at the Federal Reserve District letter rather than the series letter. So many of these bills were printed for the Bicentennial that they're still only worth face value if you get one in change. A nice crisp uncirculated one might sell for $3 to $6
2 dollars.
In circulated condition, a 1976 US $2 bill is only worth face value. The other bill, though, must have a different date because there are no 1958 US banknotes of any denomination. Please check its date again and look for the question "What is the value of a [date] US 2 dollar bill?" for values.
one dollar
The US didn't print any $5 bills dated 1976. Please check again and post a new question.
The US didn't print any $1 bills dated 1976. Please check again and post a new question.
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2 dollars.
In circulated condition, a 1976 US $2 bill is only worth face value. The other bill, though, must have a different date because there are no 1958 US banknotes of any denomination. Please check its date again and look for the question "What is the value of a [date] US 2 dollar bill?" for values.
It's still worth two dollars.
one dollar
The series 1976 $2 is quite common and still worth $2.
The US didn't print any $5 bills dated 1976. Please check again and post a new question.
The US didn't print any $1 bills dated 1976. Please check again and post a new question.
Assuming you mean the series 1976 $2 bill, it's worth $2.
One dollar.
No such bill
The face value of any coin or bank note is what is written on it, in your case, One Dollar. However there were no 1976-dated US $1 bills, only $2 bills.