Coin collectors value uncommon quarters for their age, history, and minting abnormalities. In particular, the Bicentennial Quarter is worth about $45 million USD. That's not the only valuable quarter.
The 1976 Bicentennial Quarter, in honour of the US' 200th year of independence, is the most valuable at $45 million. Most Bicentennial Quarters are nostalgic, but one minting fault makes it worth millions.
The rare and valuable 1932-D Washington Quarter is worth over $20,000. First year of Washington Quarter series, intended as a one-year commemorative design for George Washington's 200th birthday. The quarter was coined at various mints, but the Denver Mint ‘D’ mint mark is unusual.
Like the Denver collectible, the 1932-S Washington Quarter is above $20,000. Among the lowest-mintage Washington Quarters, this San Francisco-minted quarter is from the series' inaugural year.