Arno B. Cammerer replaced Albright as assistant director in 1919, serving as Mather's right-hand man in Washington and acting for him in his frequent absences over the next decade. He advanced to the new rank of associate director in 1928, then succeeded Albright as director in August 1933. Under his leadership the NPS became involved with recreational area planning and management, supervised the Civilian Conservation Corps in both national and state parks, and began to survey and record historic sites and buildings outside the parks. Strained relations with Secretary of the Interior Harold L. Ickes impaired his effectiveness and health, and he stepped down after a heart attack in 1940 to become the service's eastern regional director. He died in that position the following year.