Marching from Fort Monroe, Union Maj. Gen. George B. McClellan's Army of the Potomac encountered Maj. Gen. John B. Magruder's small Confederate force at Yorktown behind the Warwick Line.

Gen. Erasmus D. Keyes made initial contact with Confederate defensive works at Lee's Mill, an area McClellan expected to move through without resistance.

As the two armies fought an artillery duel, reconnaissance indicated to Keyes the strength and breadth of the Confederate fortifications, and he advised McClellan against assaulting them.

McClellan and his staff, ignorant of the extent of Magruder's line, assumed the Confederates had concentrated only in the immediate vicinity of Yorktown.

[8] Accounts by Magruder's soldiers indicate he marched his troops back and forth throughout his lines as a ruse to make his forces look stronger.

"This morning we were called out by the 'Long roll' and have been traveling most of the day, seeming with no other view than to show ourselves to the enemy at as many different points of the line as possible," a Louisiana soldier recorded in his diary.

Smith had two brigades (Davidson and Hancock) and a battery (Wheeler's) to hand and attempted to suppress the superior enemy artillery.

He lost the firefight and despite an order from McClellan to Keyes "to attack with all his force if only with the bayonet", Smith withdrew back to Warwick Court House.

The next day (April 6) Hancock and Burns took parts of their brigades and marched across the entire frontage to provoke enemy fire.

Smith and the attached engineer (Comstock) noted this was the only place along the river where the ground was higher on the eastern bank than the western, and hence was vulnerable.

Hancock considered this area a weak spot in the line, but his messenger was captured by the rebels en route to Smith's HQ.

Confederate Captain John Bryan suffered a similar wind mishap in a hot air balloon over the Yorktown lines.

[17] [18] It was to the amazement of the Confederates - who had estimated the Union's strength at 200,000, four times the real number - and the dismay of President Abraham Lincoln that McClellan did not attack immediately.

McClellan wished to either turn the position with an amphibious movement or find a weak point where an assault stood a reasonable chance of success.

The Navy refused to cooperate, but on 14 April, McClellan's chief engineer John G. Barnard finally reported that a weak point had been found at Dam No.

On April 15 orders were sent to Smith to occupy the Garrow Ridge and probe the rebel fortifications to see whether there was a clearing in the woods behind the crossing.

[20] Initially wildly successful in seizing the Garrow Ridge and advancing a small force to drive off the rebels, McClellan considered the task completed, and returned to his HQ to arrange for the assaulting units to move into position.

[21] Drummer Julian Scott, along with First Sergeant Edward Holton and Captain Samuel E. Pingree were awarded the Medal of Honor for their heroisim at Dam Number One.

The commander of the York River flotilla, Missroon, had consistently refused to even approach the Yorktown batteries, citing the weakness of his ship.

72,000 effectives and under the direct command of Johnston, improved their defenses while McClellan undertook the laborious process of transporting and placing massive siege artillery batteries, which he planned to deploy on May 5.

He immediately woke his brigade and set them in place to make a dawn attack, and at 5:30 a.m. the Vermonters seized the fortifications they'd been repelled by on 16 April.

He went back to Porter who this time accepted the information, ordering that reconissances be immediately sent out and for several regiments to occupy Yorktown at dawn.

Gen. William B. Franklin's division to reboard Navy transports, sail up the York River, and cut off Johnson's retreat.