The Walter Tennyson Swingle Collection contains research material and correspondence of Walter T. Swingle as well as translations and correspondence of Michael J. Hagerty. The Swingle portion of the collection is comprised of his articles, manuscripts, diaries, and most of Swingle's correspondence between 1885 and 1951.

The correspondence gives an overview of his botanical and plant introduction work as well as his personal life and travels. The bulk of the correspondence are letters from distinguished colleagues such as Herbert J. Webber, Dr. Beverly T. Galloway, W.A. Kellerman and others from the U.S. Department of Agriculture.

Also included in this group are correspondence between Swingle and David G. Fairchild, noted Florida naturalist and one of the men who conceived of a sub-tropical garden in Florida and for who Fairchild Tropical Garden in Miami, Florida is named. Their correspondence details an account of their collaborative work and friendship.

Swingle's research material includes notes, notebooks, and large number of first accounts of citrus in the Original Citrus Literature, containing a number of articles by Carolus Linnaeus.

Of special interest to the University of Miami is material dealing with Swingle's tenure as Consultant in Tropical Botany at the University, as well as some interesting material dealing with his U.S.D.A. work in Brazil in the 1930's.

The Hagerty portion of the collection consists most importantly of translations made by Hagerty of Chinese accounts on botany for the Swingle's work in the Department of Agriculture. It includes a very large translation of the Chinese accounts of citrus from the Chinese Imperial Encyclopedia which is over 500 pages long and very important to Swingle's study of citrus. Also in this portion are found a very large amount of correspondence between Hagerty and Swingle which details most of their work together for the U.S.D.A.