National Dollar Day is celebrated annually on August 8 to honor the U.S. dollar, which serves as the country's primary currency. This day provides an opportunity for individuals to learn about the history and significance of the dollar, including interesting facts such as the highest denomination ever circulated being $10,000 and the only woman featured on a U.S. paper bill being Martha Washington. Common ways to celebrate include sharing fun facts about the dollar with friends and starting a coin collection, particularly of notable dollar coins. Additionally, visiting a U.S. Mint can be a fun activity, with locations in Philadelphia, Denver, San Francisco, and West Point. The observance of National Dollar Day highlights the importance of the dollar in both domestic and international finance.