This is a 1974-S Eisenhower Dollar. It was issued to collectors in 40% silver by the U.S. Mint. These silver "Ike" dollars were available in both Uncirculated and Proof formats, but only as special-order items. The uncirculated Silver 1974-S Eisenhower Dollars, like this one are known as "Blue Ikes" because of the blue envelope in which they were sold. This example does not have the blue fold, just the heat sealed sleeve which is embossed "United States Mint."
This example looks to be in Gem uncirculated condition. Most of the marks you see are actually on the surface of the plastic bag, and not on the coin. The coin does have a clash mark on the N in "IN GOD WE TRUST", and there are a couple of tiny tarnish spots, but the coin is in very nice condition. The blue medallion lost a spec of silver foil, and you can see that speck loose in that compartment.