Horace M. Albright came to the Interior Department from California in 1913 at the age of 23. After Mather's arrival Albright assisted him in overseeing the department's national parks and monuments and working for passage of the National Park Service legislation. Appointed NPS assistant director in May 1917, he acted as director for nearly two years while Mather was disabled by depression and launched the bureau's operations. From 1919 to 1929 he superintended Yellowstone National Park but continued to play a leading role in servicewide affairs. As Mather's successor in January 1929, he engineered the further expansion of an essentially western, natural park system to a truly national park system encompassing historic sites and memorials. He left for a private business career in August 1933 after obtaining the Agriculture and War departments' national monuments and military parks and the national capital parks, but he retained close ties to the NPS until his death in 1987.