A member of the Osage tribe, Miller converted to Christianity and became convinced that he was both the Messiah and the reincarnation of the earlier Indian leader Tecumseh. Promising his followers that the destruction of the demonic whites would lead to "a new heaven on earth", he led a successful assault on Michigan City in July 1839. Five thousand white civilians were massacred after the city was taken.
The C.N.A., in its first unified military action since the Trans-Oceanic War, dispatched a large army under the command of Winfield Scott to avenge the massacre and retake the city. This was accomplished in October, and Miller was executed along with all surviving members of his army.