Jack in the Box is an American fast-food restaurant chain that was founded in 1951 by Robert O. Peterson in San Diego, California. The company operates over 2,200 restaurants in 21 states and Guam. The chain is known for its signature item, the Jumbo Jack, as well as its tacos and curly fries. Jack in the Box also owns the Mexican fast-food chain Qdoba, which operates over 700 locations in the United States and Canada. The company is headquartered in San Diego, California.