Costco is the largest chain of membership warehouse stores in the United States. Founded in 1976 as Price Club in San Diego, California, and seven years later as Costco in Seattle, Washington, Costco was the third largest retailer in the United States and the ninth largest in the world in 2009. Costco is the founder of the membership-based wholesale warehouse club and has been committed to providing its members with the highest quality brand name products at the lowest possible prices since its inception. Currently, Costco has more than 500 stores in seven countries around the world, most of which are located in the United States, with Canada being the largest foreign market, primarily near the capital city of Ottawa. The global corporate headquarters is located in Issaquah, WA, with a flagship store in nearby Seattle.