Arlington Line

The Arlington Line was a series of fortifications that the Union Army erected in Alexandria County (now Arlington County), Virginia, to protect the City of Washington during the American Civil War (see Civil War Defenses of Washington and Washington, D.C., in the American Civil War).

In May 1861, federal troops seized much the County and immediately began constructing a group of forts near Washington on the Virginia side of the River to protect the capital city.

These and larger fortifications later constructed nearby became known as the Arlington Line.

The Arlington Line was never attacked, even after the federal defeat at the Second Battle of Bull Run (Manassas) in late August 1862.

Major Daniel Phineas Woodbury was the Union engineer who designed and constructed the Arlington Line.