Here are all the publications I found valuable in researching the legend of Hiawatha, Deganawidah, and the founding of the Iroquois League, Confederacy, or Confederation. Most links are for more info at Amazon.com, an affiliate. Please note that this is the historical Hiawatha, not the cultural travesty in Longfellow’s poem!
The Great Law and the Longhouse: A Political History of the Iroquois Confederacy, by William N. Fenton, University of Oklahoma Press, Norman, Oklahoma, 1998. Includes the most thorough and up-to-date overview of the League legend, its evolution, and its variants, as well as extensive material on the League itself.
The Iroquois Book of Rites, by Horatio Hale, Brinton, Philadelphia, 1883; reprinted by Iroqrafts, Ohsweken, Ontario, 1990, and others. Hale was a pioneering nineteenth-century linguist, and this book includes his version of the Hiawatha story, based on interviews with the Iroquois. It is one of the earliest recorded versions, and the one probably closest to historical fact. The section on Hiawatha is drawn almost entirely from an address of Hale’s that had been published as the booklet Hiawatha and the Iroquois Confederation: A Study in Anthropology, private printing, Salem, Massachusetts, 1881, and as “A Lawgiver of the Stone Age,” in Proceedings of the American Association for the Advancement of Science, Vol. 30, 1882. Hale’s book includes everything important from that address and adds useful notes—but if you don’t have the book, you can read the address in a slightly abridged form on Mark Shepard’s Peace Page.
Parker on the Iroquois, by Arthur C. Parker, edited with an introduction by William N. Fenton, Syracuse University Press, Syracuse, New York, 1968. Includes a complete reprint of Parker’s influential collection The Constitution of the Five Nations, which has several versions of the legend. As a needed balance, Fenton’s introduction points out the questionable nature of Parker’s sources.
The White Roots of Peace, by Paul A. W. Wallace, University of Pennsylvania Press, Philadelphia, 1946. A popular but unreliable interpretation.
Wilderness Messiah: The Story of Hiawatha and the Iroquois, by Thomas Henry, Crown, New York, 1955. Especially good for background material.
Concerning the League: The Iroquois League Tradition as Dictated in Onondaga by John Arthur Gibson, edited and translated by Hanni Woodbury, Algonquian and Iroquoian Linguistics, Winnipeg, Manitoba, 1992. With footnotes.
The Founders of the New York Iroquois League and Its Probable Date, by William M. Beauchamp, New York State Archeological Association, Rochester, New York, 1921.
“Legend of the Founding of the Iroquois League,” by J. N. B. Hewitt, in The American Anthropologist, Vol. 5, April 1892.