The product is a complete set of State Quarters First Day Covers. This set includes coins from all 50 states and 6 territories, uncirculated and in clad composition. Each quarter is a piece of American history, minted in either Philadelphia or Denver from 1999 to 2009. These United States coins bear the unique designs of each state, making them a valuable collector's item. The State Quarters First Day Covers come with certification by the U.S. Mint, adding to their authenticity and appeal to numismatists.