Ace Hardware Corporation is a hardware retailers' cooperative based in Oak Brook, Illinois, United States. It is the world’s largest hardware retail cooperative, and the largest non-grocery American retail cooperative. Founded in 1924 as "Ace Stores", the company changed its name to "Ace Hardware Corporation" in 1931. It grew dramatically following World War II, more than tripling its sales between the late 1940s and 1959. After the retirement of longtime president and founder Richard Hesse in 1973, Ace was sold to its retailers, becoming a retailer-owned cooperative. It first reached $1 billion in wholesale sales in 1985 and $5 billion in 2015. As of 2016[update], it has over 4,800 locations in 60 countries. Ace operates 17 distribution centers in the United States, and additional distribution facilities in China, Panama, and United Arab Emirates. In 1924, to increase buying power and profits, entrepreneurs Richard Hesse, E. Gunnard Lindquist, Frank Burke and Oscar Fisher united their Chicago, Illinois hardware stores into "Ace Stores". The company was named after the ace fighter pilots of World War I, who were able to overcome all odds. Ace Stores was incorporated in 1928, and the company opened its first warehouse a year later. In 1931, the name was changed to Ace Hardware Corporation.