Under Balanchine's tutelage at American Ballet, Lew Christensen became the first American-born "danseur noble". The United States Army drafted Christensen to fight in World War II. After the war ended, he joined Balanchine's and Lincoln Kirstein's Ballet Society (soon to become New York City Ballet), eventually becoming ballet master; he served in the role from 1946 until 1950. In 1951, he joined his brother Willam as co-director of San Francisco Ballet. When Willam moved to Salt Lake City later that year, Lew took over as full director of SF Ballet; he held the position until 1976, when Michael Smuin joined him as co-director. Lew Christensen remained SF Ballet co-director until 1984, the year of his death.