Shortly after the outbreak of World War II in 1939, the Serkins and Busches immigrated to the United States, where Serkin taught several generations of pianists at the Curtis Institute of Music in Philadelphia. From 1968 to 1976 he served as the Institute's director. He lived with his growing family, first in New York, then in Philadelphia, as well as on a dairy farm in rural Guilford, Vermont. In 1951, Serkin and Adolf Busch founded the Marlboro Music School and Festival in Marlboro, Vermont, with the goal of stimulating interest in and performance of chamber music in the United States. He made numerous recordings from the 1940s into the 1980s, including one at RCA Victor of Beethoven's Piano Concerto No. 4 in 1944, with the NBC Symphony Orchestra conducted by Toscanini. Most of his recordings were made for Columbia Masterworks, although in the 1980s he also recorded for Deutsche Grammophon and Telarc. Serkin admired the music of Max Reger, which he discovered while working with Adolf Busch. In 1959, he became the first pianist in the United States to record Reger's Piano Concerto, Op. 114, with Eugene Ormandy and the Philadelphia Orchestra.