This is the United State Mint 50 State Quarters U.S. Mint Proof Set from 1999. Coins come in the original one piece box with the COA.

The coins that are this 1999 Statehood Quarter Set are:

1999 Delaware Clad Gem Proof Statehood Quarter
1999 Pennsylvania Clad Gem Proof Statehood Quarter
1999 New Jersey Clad Gem Proof Statehood Quarter
1999 Georgia Clad Gem Proof Statehood Quarter
1999 Connecticut Clad Gem Proof Statehood Quarter