Rebellion in the Backlands by Euclides da Cunha.

Rebellion in the Backlands is not fiction but rather a factual account of an actual historical event. The event—a rebellion led by a charismatic religious fanatic against the federal government of Brazil—might have sunk into obscurity but for Cunha’s account, which does not merely report the event but also defines and interprets its significance. As a result, Rebellion in the Backlands has been called Brazil’s national epic, and its influence on Brazilian fiction—indeed, South American fiction—has been substantial. The work itself, with its plot buildup, might be said to anticipate the so-called nonfiction novel of later decades.