Complex sentence: The area becomes populous again as it nears the city of Vincennes at mile 441; founded by the French about 1720, it is the oldest European settlement in Indiana, and amongst the oldest in the American Midwest.
Split into simpler sentences: The area becomes populous again as it nears the city of Vincennes at mile 441. Founded by the French about 1720, Vincennes is the oldest European settlement in Indiana, and among the oldest in the American Midwest.