WILLIAMSBURG, Va. — The College of William and Mary has long claimed fame as the “Alma Mater of a Nation,” pre-dating the American Revolution. Now archaeologist say weeks of fresh excavation have uncovered the remnants of earthworks apparently dug by occupying Union troops — new evidence that the colonial-era school had an outsized role in the Civil War.

Buried just beneath the surface lies a reminder that the country’s second-oldest college still bears the scars of America’s bloodiest conflict. Archaeologists in recent weeks have probed a defensive encampment in downtown Williamsburg. It was here that Union forces survived raids by Confederate troops from 1862 to 1865 and kept a small portion of secession-minded Virginia under federal control.

Joe Jones, director of the William and Mary Center for Archaeological Research, said finding evidence of the fortifications and so many well-preserved artifacts in such a small space on the campus is unusual.

“From 1862 to 1865 this was one of the front lines of the Civil War,” Jones told The Associated Press. He said the new finds are already triggering a new round of discussion about the school’s Civil War chapter on the 150th anniversary of that conflict — a chapter long overshadowed by the school’s colonial past.

William and Mary long has touted its ties to several of America’s founding fathers. It was here, as the college boasts on its website, that a 17-year-old George Washington received his surveyor’s license and where Thomas Jefferson received his undergraduate education, much like future presidents John Tyler and James Monroe.

But Jones said that’s not to overlook its history in later times.

The initial discovery that there may be more Civil War artifacts buried on the grounds occurred last fall when the college was doing survey work for some new utility lines for renovations on a building originally constructed in 1723. The historic school was chartered in 1693 and is home to the oldest college building in the United States, built in 1700.

Archaeologists also discovered the remains of a brick well that was dug up — and then covered over again — by Union troops when they took over the abandoned campus and began tearing and burning down some of its buildings. For about three years, 1,500 troops encamped on the college grounds, about 50 miles from the former Confederate capital in Richmond.