Complex sentence: Because of the free blacks'contributions during the Natchez War, the French allowed them to join Louisiana's militias, which gave them more connections into the colonial society, where they achieved an independent social status between the French colonists and slaves.
Split into simpler sentences: Because of the contributions of the free men of color during the Natchez War, the French allowed them to join Louisiana's militias. This gave them important connections into the colonial society, contributing to their achieving an independent social status between the French colonists and slaves.