wilderness, land retaining its primeval character with the imprint of humans minimal or unnoticeable. In the United States, the Wilderness Act of 1964 established the National Wilderness Preservation System with a nucleus of 9 million acres (3.6 million hectares) of land in 54 different areas, mostly in Western states, and provided for the designation of new wilderness areas. By 1992, the total had risen to 95 million acres (38.4 million hectares) in 708 parcels of land. Alaska, with 57.6 million acres (23.3 million hectares), was by far the leading repository of wilderness; Ohio had but 77 acres, and some states had none, although designated areas included several Eastern locations where signs of civilization were substantially erased. Wilderness lands are to be preserved in their natural condition, wild and undeveloped, both for their own sake and for humankind's solitude and enjoyment of their beauty. The idea of wilderness has deep roots in American thought (see environmentalism). In the 17th cent. William Penn decreed that one acre of forest be left wild for every five that were cleared. Henry David Thoreau believed that the existence of wilderness was justified by the inspiration people could draw from it.

Wilderness campaign, in the American Civil War, a series of engagements (May-June, 1864) fought in the Wilderness region of Virginia. Early in May, 1864, the Northern commander in chief, Grant, led the Army of the Potomac (118,000 strong) across the Rapidan River into the Wilderness, a wild and tangled woodland c.10 mi (16 km) W of Fredericksburg. Grant planned to clear the Wilderness before trying to destroy the smaller Confederate Army of Northern Virginia (60,000 troops) under Robert E. Lee. But Lee advanced on the Union troops while they were still in that area, causing Grant to face about and order an attack. The nature of the terrain made the battle of the Wilderness (May 5-6) a disjointed but bloody fight. After the repulse of a Union attack on May 6 through the opportune arrival of the 1st Corps under James Longstreet, Lee counterattacked, and the battle became stabilized. Grant then pushed ahead by Lee's right, heading toward Spotsylvania Courthouse, c.12 mi (19 km) to the southeast. Lee, anticipating the move, was soon entrenched there. In the battle of Spotsylvania Courthouse (May 8-19), Grant unsuccessfully hammered away at the Confederate lines. The bloodiest fighting of this battle occurred on May 12 when the Union assault on the salient forming the Confederate center (the Bloody Angle) was repulsed after initial success. Lee confronted Grant's next move from a position S of the North Anna River, so impregnable that even Grant did not attack. By the beginning of June both armies were near Richmond. Fearing that Lee might withdraw within the defenses of the capital, Grant made another unsuccessful frontal assault on his strongly entrenched enemy in the battle of Cold Harbor, June 3, 1864. The Union lost 7,000 men in a few hours—the most horrible slaughter of the war. After several days of desultory trench fighting Grant then withdrew, crossed the James River, and moved against Petersburg. He had lost about 60,000 men in the campaign, and although Lee's army sustained the proportionately larger loss of 20,000, it was by no means destroyed.

Wilderness Road, principal avenue of westward migration for U.S. pioneers from c.1790 to 1840, blazed in 1775 by the American frontiersman Daniel Boone and an advance party of the Transylvania Company. Feeders from the east (Richmond, Va.) and the north (Harpers Ferry, W.Va.) converged at Fort Chiswell in the Shenandoah valley. Boone's road ran southwest from there through the valley, then W across the Appalachian Mts. and through Cumberland Gap into the Kentucky bluegrass region and to the Ohio River. The road followed old buffalo traces and Native American paths, but much of it had to be cut through the wilderness. In the early years, many travelers fell victim to hostile Native Americans.

After Kentucky became a state in 1792, the road was widened to accommodate wagons. Private contractors, authorized to keep up sections of the road, charged tolls for its use. With the building of the National Road, the Wilderness Road was neglected and finally abandoned in the 1840s. Since 1926 the Wilderness Road has been a section of U.S. Route 25, the Dixie Highway.