Where is the Federal Reserve District letter on a 1976 US 2 dollar bill?

It's inside the Federal Reserve Seal, located on the left side of the bill's front, very much like the seal on a $1 bill. The issuing district is shown in small type surrounding the large district ID letter.

The term "issuing district" does NOT mean where the bill was printed, simply which Federal Reserve District requested and distributed it. All 1976 $2 bills (in fact, all US bills up till 1991) were printed at the Bureau of Engraving and Printing in Washington.