Consists of diaires, correspondence, published and unpublished writings, medals, awards, photographs, and scrapbooks of Hall (Princeton Univerrsity Class of 1910). The collection contains diaries Hall kept throughout his life which chronicle his travels and his reflections on transportation conditions; personal and business correspondence; official documents and reports from his tenure with the American Financial Mission to Persia (1922-1927) which reflect his work as a provincial administrator. (Many of these documents are in Farsi, and several are in French; most are dated in the Iranian calendar.) There are copies of his published writings including JOURNEY TO THE END OF AN ERA, which describes a 45,000 mile motor trip around the world (1912-1913), and BIRD OF TIME, which contains reminiscences of his travels, experience in World War I, and life in Vezelay, France. Photographs document Hall's world travels and his activities in Persia and during World War I when he served as a U.S. Army Air Corps officer. Included are records of his military service, appointments, awards, citations, and medals.

Hall's diaries are detailed and especially valuable for their observations on international travel and transportation conditions. They reflect his fascination with the automobile and aeroplane. Aviation, and his belief in its potential for both defense and commerce, was a life-long commitment. Letters to his family contain analyses of political and social factors in countries where he traveled and was stationed. His assessments and predictions concerning World War II, and later, the future of Indochina, are astute.

Of particular interest are the materials which devolve from Hall's work as a provincial administrator with the American Financial Mission to Persia (1922-1927). Many of these official documents are in Farsi, and several are in French; most are dated in the Iranian calendar. The American Financial Mission paid particular attention to the census value of tax rolls, and the documents contain lists of names and tribal organization charts. Details of agricultural production and land use, observations on uprisings, information on oil concession, the opium trade and pearl fishing industry, and comments on the political regime are highlighted.