With the opening today of a new, $103 million visitor center at Gettysburg National Military Park, Cemetery Ridge is undergoing the most radical change to its look and feel in a generation. The new visitor center, hidden in a hollow behind the ridge, has made both the old visitor center and the Cyclorama Building -- designed by the renowned architect Richard Neutra in the 1960s -- obsolete. And so, in an effort to return the battlefield to its original state, the National Park Service is about to tear down both structures, which have for decades sat squarely in the middle of the Union lines.

These changes are part of a rehabilitation project that has produced dramatic changes on the battlefield. In the early 1990s, power lines that ran along the Emmitsburg Road -- one of several historic roads that converge at Gettysburg -- were buried underground. In 2000, a hulking observation tower -- a tourist trap that offered paying visitors the chance to survey the battlefield from on high -- was demolished. And today, the Park Service continues to remove trees and build fences, in an effort to re-create the original sightlines of the 1863 battle.

It's not just physical changes. Exhibits and films at the new museum are focused on the context of the war, the issue of slavery, the economic challenges faced by North and South -- a shift in emphasis that is happening throughout the National Park Service's Civil War sites.