In 1903, Chicago fell in love with flying. Enterprising people opened airfields and designed and built aircraft, and aviators won big money at air meets. After World War I, aviation was a serious matter with explosive commercial potential. A transcontinental airmail service was established and became the impetus for the first airlines. Aspiring to be first in aviation, the City of Chicago considered each of its existing airfields to develop into its new, modern municipal airport. It chose none of them and instead decided on a square mile of property 10 miles southwest of the city as the location for what would soon become the World s Busiest Airport. "