President Franklin D. Roosevelt established the United States National Archives and Records Administration (NARA) in 1934, the same year that Theodore Roosevelt Schellenberg earned his doctorate in history from the University of Pennsylvania and began a career in archives. Schellenberg slowly and surely climbed the archival ranks, holding federal posts in Washington, D.C., and teaching archival-training courses at local universities; he later lectured on a variety of topics relating to archives in Latin America, Australia, and New Zealand. In 1950 Schellenberg was appointed to the prestigious position of director of Archival Management at NARA. Schellenberg soon published Modern Archives: Principles and Techniques (1956), and in the years before his retirement in 1963 he would go on to publish dozens of works on archival history and practice, both in the United States and overseas. Modern Archives is arguably the most enduring of Schellenberg’s writings, a kind of textbook for United States archivists that argues the importance and European origins of United States archives, examines the distinguishing characteristics of archival records and institutions, and outlines approaches to primary archival functions, from appraisal to documentary publication. Both records-management and archival-management guidelines are often illustrated by way of contrasting United States principles and techniques with those of other nations, making clear the latter’s "essential nature." Given this, it is perhaps unsurprising that even fifty years after its original publication Modern Archives remains canonical reading for United States archivists.