Longfellow claimed that, while at college (Bowdoin), he read some works by John Gottlieb Ernestus Heckewelder, a missionary who worked among the Indians of Pennsylvania and New Jersey in the 1810s, which had an impact on him.
He was also moved by a visit of Black Hawk to Boston -- Longfellow saw him in the Boston Common in the 1830s.
There was a musical treatment of the Hiawatha story soon after Longfellow's book hit the shelves. Robert Stoepel's Hiawatha: an Indian Symphony premiered in 1858. Another musical treatment was Arthur Foote's The Farewell of Hiawatha in 1888.
Dignity, always dignity.
