The following is from The Peninsula, McClellan's Campaign of 1862 by Alexander Stewart Webb, 1882
This paragraph and a half describes Magruder's first line of defense, constructed on the Peninsula about seven miles closer to Newport News. Magruder's second line was the one from Gloucester Point-Yorktown-Mulberry Island (the Warwick Line). Magruder decided he could not stand at the first line after he sent 5,000 troops south of the James to counter Burnside's forces due to orders from Richmond in early March.
This paragraph and a half describes Magruder's first line of defense, constructed on the Peninsula about seven miles closer to Newport News. Magruder's second line was the one from Gloucester Point-Yorktown-Mulberry Island (the Warwick Line). Magruder decided he could not stand at the first line after he sent 5,000 troops south of the James to counter Burnside's forces due to orders from Richmond in early March.
The Confederate attitude in this quarter had been, from the first, that of defence. For some time after the affair of Big Bethel, June 10, 1861, they had made Yorktown their base of observation, with posts thrown out several miles in advance. Major-General J. Bankhead Magruder, late of the United States Army, commanded. By March 1, 1862, Magruder had laid out, and partially completed, three defensive lines across the Peninsula, from Williamsburg down toward Fort Monroe. What he proposed and describes as his " real line of defence positions," was the one at the front, seven miles below Yorktown ; or at that point between Howard's and Young's Mills, where the setting back of the Poquosin River from the York and the mouths of the Warwick and Deep Creek, on the James, contract the intervening solid ground to the short distance of three miles. " Both flanks of this line," says Magruder, "were defended by boggy and difficult streams and swamps. In addition, the left flank was defended by elaborate fortifications at Ship Point, connected by a broken line of redoubts crossing the heads of the various ravines emptying into York River and Wormley's Creek, and terminating at Fort Grafton, nearly in front of Yorktown. The right flank was defended by the fortifications at the mouth of "Warwick River and at Mulberry Island Point, and the redoubts extending from the Warwick to James River. Intervening between the two mills was a wooded country, about two miles in extent. This wooded line, forming the centre, needed the defence of infantry in a sufficient force to prevent any attempt on the part of the enemy to break through it. In my opinion, this advanced line, with its flank defences, might have been held by 20,000 troops. With 25,000 I do not believe it could have been broken by any force the enemy could have brought against it. Its two flanks were protected by the Virginia (Merrimac) and the works on one side, and the fortifications at Yorktown and Gloucester Point on the other.
His force being reduced by detachments sent across the James to Suffolk and Portsmouth, Magruder abandoned this advanced line about March 1st, and fell back to his second line, running from Yorktown on his left along the Warwick River to Mulberry Island, and the James upon the right. ...