The share of U.S. school-age children attending private elementary schools peaked during the postwar boom of the late 1950s and early 1960s, reaching 15 percent in 1958. By the mid-1970s, it had fallen to 10 percent and remained quite steady for the rest of the 20th century. Those relatively stable numbers mask significant changes in the mix of school types that make up the private-school market, however, driven by widespread closures of Catholic schools. In 1965, 89 percent of American children who attended a private elementary school were enrolled in a Catholic school; in 2013, the comparable figure was 42 percent. To learn more about private-school enrollment trends, read “Who Goes to Private School?” from the Fall 2018 edition of Education Next.