Property of Dyersville, Iowa Drinking Team T-Shirt

This design is one-of-a-kind and found only at Dubuque Clothing Co. — the Property of Dyersville, Iowa Drinking Team T-Shirt is printed on a premium tee using high-quality, soft inks built to last long after the party's over.

The shamrock on this tee carries more history than most people realize. Irish legend holds that Saint Patrick himself used the three-leafed plant as a teaching tool in the 4th century, holding it up to explain the Holy Trinity to the people he was converting. The earliest written record of the custom comes much later, from 1726, when Irish botanist Caleb Threlkeld noted that "this plant is worn by the people in their hats upon the 17th day of March yearly," and he was the one who first tied that tradition back to Patrick's Trinity lesson. By the 17th century, poor Irish churchgoers were pinning shamrocks to their clothes for the feast day simply because it was a symbol anyone could afford, and when Irish immigrants carried the custom to America in the 18th century, they leaned on printed images of the shamrock whenever the real plant wasn't available. The symbol's status only grew from there — when Hallmark started producing St. Patrick's Day greeting cards in the 1920s, the shamrock became their go-to design, and Irish brands like Aer Lingus later adopted it too, cementing it worldwide as shorthand for all things Irish.

Reference: The Shamrock's Journey to St. Patrick's Day Symbol - TIME