The Official Brand of the United States Polo Association. Steeped in classic American style, the apparel draws inspiration from the rich heritage of the game and its spirited athletes. Our U.S. Polo Assn. (USPA) online store offers an extensive selection of classically styled, high quality, casual clothing, including denim, khakis, polo shirts, tees. Our U.S. Polo Assn. (USPA) online store offers an extensive selection of classically styled, high quality, casual clothing, including denim, khakis, polo shirts, tees. We are the only brand that is officially part of the United States Polo Association. Learn about the brand, the sport, and our place in history as you discover all that U.S. Polo Assn. has to offer. The United States Polo Association® is organized for the purposes of promoting the game of polo. It is the largest voluntary sports organization for polo in North America Shop items from U.S. Polo Assn. at Walmart.com and learn more about how you can save money on the best U.S. Polo Assn. products to help you live better. The official U.S. Polo Assn. (USPA) web store features a wide range of high-quality, classic casual wear, such as polo shirts, t-shirts, denim, and khakis.