Since 1840. It began as "Breeder's Day", a single day livestock show and mule market event held on the first Monday in April. Over time, "Mule Day" evolved from a single day event into a multi-day festival, attracting thousands of attendees, lasting almost a week. The heavy involvement of Maury County in the mule industry has caused the event to grow over time into "one of the largest livestock markets in the world." Activities include mule shows, mule pulling, arts and crafts, flea market, knife show, liars contest, pancake breakfast, parade and a beauty pageant to select Mule Day Queen.