Complex sentence: Known as the Warwick Line, this second, and by far largest of the 3 defensive lines, was about a dozen miles east of Williamsburg, along the Warwick River, and was anchored by Yorktown on the north and Mulberry Island on the south.
Split into simpler sentences: Known as the Warwick Line, this second, and by far largest of the three defensive lines, was about a dozen miles east of Williamsburg, along the Warwick River. It was anchored by Yorktown on the north and Mulberry Island on the south.