Complex sentence: From the time of their arrival, the German immigrants began speaking French and intermarried with the early French settlers; and over the subsequent decades they intermarried with the descendants of the latter as well as the Acadians.
Split into simpler sentences: From the time of their arrival, the German immigrants began speaking French and intermarried with the early French settlers. Over the subsequent decades they intermarried with the descendants of the latter as well as the Acadians.