What is a GSA Morgan Silver Dollar?

By GovMint :

A GSA Morgan Silver Dollar refers to a specific type of Morgan Silver Dollar that was stored in the U.S. Treasury vaults and later released for sale by the General Services Administration (GSA) in the 1970s. These coins were part of a hoard of uncirculated silver dollars that had been held in government vaults for decades. The GSA conducted auctions to sell these coins to the public, creating excitement among coin collectors for this new hoard of Morgan Silver Dollars.

Sources Used:

https://coinweek.com/numismatic-history-the-gsa-hoard-of-cc-mint-morgan-silver-dollars/