Cahill returned to the East Coast and settled in Newark, New Jersey in 1910. It was there that he decided to establish a national governing body for soccer. He traveled to Stockholm in 1912 to attend the FIFA annual congress with the intention of gaining recognition for the American Amateur Football Association, a group he co-founded. This attempt failed, though he ultimately achieved his goal when he formed the United States Football Association, which would later become the United States Soccer Federation. He served three separate terms as the Executive Secretary of the USFA; 1913-1921, 1923-1924 and a final term in 1928. In 1921 Cahill was instrumental in forming the American Soccer League, which was the first serious attempt to establish a professional league in the United States. He served as the organization's secretary in its early years.