The university named history chairperson Herbert E. Bolton its founding director, a position he held for the library's first 22 years. In his dual capacity, he made Bancroft Library a great research center for American history in congruence with the department's rise to prominence. Until the decade of the 1960s, The Bancroft Library continued to focus exclusively on the history of the American West, particularly the borderlands of northern Mexico and the southern United States, from Florida to California, an area associated with the research interests of long-time directors Bolton (1918–1940) and George P. Hammond (1946–1966).