Complex sentence: The house was the principal family residence during Eugene O'Neill's childhood; as a child Eugene would spend much of the year traveling with his actor father as the latter toured from city to city, but the family would return to this cottage each summer.
Split into simpler sentences: The house was the principal family residence during Eugene O'Neill's childhood. As a child Eugene would spend much of the year traveling with his actor father as the latter toured from city to city, but the family would return to this cottage each summer.