City (pop., 2000: 40,517) and resort, southeastern New Jersey, U.S. Lying on narrow Absecon Island, the resort began to be developed in the mid-19th century. Amusement piers were constructed, and the first beachfront boardwalk was built there in 1870. The Miss America Pageant was established in Atlantic City in 1921. After World War II the city began to decline. In 1976 the state approved legalized gambling, and extensive development in Atlantic City provided a huge influx of money to the resort, but much of the surrounding area remained impoverished.