In the spring of 1907, Father John B. Young, pastor of St. Francis Xavier Church in Manhattan, was in Rome on Vatican business and additionally to seek out a replacement for his organist Gaston Dethier, who was leaving to pursue a concert career. Upon hearing Yon play, Father Young was sufficiently impressed to offer him a three-year contract. Thus Yon at age 21 came to the United States, where from 1907 until 1926 he was the organist of St. Francis Xavier Church. He joined his brother S. Constantino Yon, who had preceded him and held a similar position at St. Vincent Ferrer Church.