In May 1864, Ulysses S. Grant opened his Overland Campaign by crossing the Rapidan River with about 118,700 men and a supply train of over 4,000 wagons. This episode explains why that army halted in the Wilderness, roughly 70 square miles of secondary growth left after clear-cutting for tobacco and iron furnaces in Spotsylvania and Orange counties. Robert E. Lee, with about 66,000 men, struck while the Union columns were tangled in scrub pine, briars and vines that cancelled the advantages of numbers, artillery and cavalry.

On May 5, Lieutenant Colonel John Hammond’s 5th New York Cavalry fought dismounted with Spencer carbines and delayed a Confederate corps for hours. At Saunders Field the Iron Brigade was hit in the flank, and muzzle flashes set the dry woods on fire, burning wounded men where they lay. On May 6, James Longstreet’s flank attack along an unfinished railroad bed rolled up the Union line until his own men shot him, near where Stonewall Jackson fell a year earlier. Despite nearly 29,000 casualties, Grant turned his army south toward Spotsylvania instead of retreating.

• Lost Union soldiers wandered into the Widow Tapp Farm, Lee’s headquarters, and ran back into the woods.
• Confederate prisoners believed Hammond’s few hundred cavalrymen had been a full infantry brigade.
• Longstreet’s corps reached the field after a 32-mile march.
• Grant rebuked an officer who warned that Lee would land in the army’s rear, telling his staff to think about what they would do to Lee instead.
• Union soldiers cheered when they realized the night march of May 7 was heading south.