Allatoona Pass, Georgia

Atlanta’s sprawl threatens to engulf the scene of a fight in October 1864 for one of Gen. William T. Sherman’s supply lines.

Mansfield, Louisiana

The Red River Campaign battleground owes its precarious status to adjacent lignite mining and residential development.

Brice’s Cross Roads, Mississippi

An influx of traffic surrounding the location of a humiliating 1864 Union defeat may squeeze it off the map.

Raymond, Mississippi

Grant’s victory here in May 1863 encouraged him to move on to Jackson. Today, that city’s development is encroaching on the wooded valley.

Fort Fisher, North Carolina

The list’s only site not menaced by human hands, this coastal fortification, which guarded Wilmington until its fall in early 1865, is being eroded by the waters of the Atlantic.

Gettysburg, Pennsylvania

Even the war’s most famous battlefield is jeopardized; nearby commercial zoning is the culprit.

Stones River, Tennessee

The expansion of a highway interchange and its imminent strip of restaurants and gas stations endangers the pristine location of a tactical defeat for the Union in 1863.

Loudoun Valley Sites (Aldie, Upperville, and Middleburg), Virginia

Developers are eyeing this trio, the setting for a series of skirmishes in June 1863, for roads and subdivisions.

The Wilderness, Virginia

A building boom along the neighboring Orange turnpike imperils the dense woodland where, in 1864, Lee first clashed with Grant.

Harpers Ferry, West Virginia

A 188-home subdivision has already been platted on the site of the arsenal, with industrial projects looming in the future.