Complex sentence: Many of them had become the placées of white French and Spanish Creole men, and this incurred the jealousy and anger of their wives, mothers, sisters, daughters and fiancées.
Split into simpler sentences: Many of them had become the placées (mistresses) of white, French, and Spanish Creole men. This incurred the jealousy and anger of their wives, mothers, sisters, daughters and fiancées.