Solon Justus Buck was the Second Archivist of the United States.
His academic career, never straying very far from his interest in the history of agricultural communities, started with a brief appointment to Indiana University followed by two years at the University of Illinois, which he left for the University of Minnesota in 1914, becoming also superintendent of the Minnesota State Historical Society. During his long tenure in Minnesota he fought hard for the state's history, helping organize county historical societies, founding a quarterly periodical, and moving the Historical Society from the basement of the State Capitol to its own building.
In 1931, Buck was appointed professor of history at the University of Pittsburgh, and when the U. S. National Archives were established in 1935 he was tapped to be Assistant Director, then in 1941 the second Archivist of the United States. In 1948, he joined the Library of Congress as chief of the Manuscript Division, then as Assistant Librarian until his retirement in 1954. He also served as the seventh president of the Society of American Archivists, from 1949 to 1951.