From the Wikipedia article:
The Song of Hiawatha is an 1855 epic poem in trochaic tetrameter by Henry Wadsworth Longfellow which features Native American characters. The epic relates the fictional adventures of an Ojibwe warrior named Hiawatha and the tragedy of his love for Minnehaha, a Dakota woman. Events in the story are set in the Pictured Rocks area of Michigan on the south shore of Lake Superior. Longfellow's poem is based on oral traditions surrounding the figure of Manabozho, but it also contains his own innovations.
Longfellow drew some of his material from his friendship with Ojibwe Chief Kahge-ga-gah-bowh, who would visit at Longfellow's home. He also had frequent encounters with Black Hawk and other Sauk people on Boston Common, and he drew from Algic Researches (1839) and other writings by Henry Rowe Schoolcraft, an ethnographer and United States Indian agent, and from Heckewelder's Narratives. In sentiment, scope, overall conception, and many particulars, Longfellow insisted, "I can give chapter and verse for these legends. Their chief value is that they are Indian legends."