For the history of the short-lived British province of East Florida the main source is undoubtedly the papers in the Public Record Office in London, of which almost all of first importance are available in the form of transcripts or photostats in the Library of Congress. Aside from this, perhaps the best single collection of manuscript material is that in the William L. Clements Library at the University of Michigan in Ann Arbor. The nucleus of the library is its collection of rare books dealing with America, mainly in the colonial and revolutionary periods, but it possesses also an important map division, and a collection of manuscripts which no student of America history, in the period of the War of Independence, can possibly afford to overlook. This manuscript collection is in part made up of manuscripts of American authorship but it is the British manuscripts, including the Shelburne, Gage, Clinton, Germain, Knox and Sydney papers, which for many are the more valuable.
Mowat, Charles L.
"Material Relating to British East Florida in the Gage Papers and Other Manuscript,"
Florida Historical Quarterly: Vol. 18
, Article 6.
Available at: https://stars.library.ucf.edu/fhq/vol18/iss1/6