1976-S $1 Silver MS68 Certification #21801954, PCGS #7422
This is one year Type coin since it carries the Bicentennial design. It also was composed of mostly silver and has an S mint mark so it is different than the other Bicentennial coins since all others were made out of clad. It is also the last year in which the Eisenhower Dollar was struck and the last of the large Dollar coins.
Examples in circulated grades up to MS65 are very common. In MS66 to MS67 grade they are a little tougher to find but they exist in the tens of thousands. In MS68 they are really scarce and there are probably no more than 1,000 examples in this grade with none being finer.