The federal government moved to end a 27-year modern-day skirmish at Gettysburg National Military Park by filing suit yesterday to tear down a privately owned, 310-foot observation tower that history buffs have repeatedly denounced as a national eyesore spoiling one of the nation's most important Civil War landscapes.

The government exercised its power of eminent domain in U.S. District Court in Harrisburg, Pa., against the owners of the National Tower, a commercial tourist attraction on private property near the fields where Union troops turned back 12,000 Confederate soldiers in the attack called Pickett's Charge.

Congress has given the National Park Service about $6 million to acquire the tower and two other parcels inside the Gettysburg park boundaries. The federal court will determine fair compensation for the taking of the land after hearing arguments from the Justice Department and the property owners.

"We didn't want the tower in the park in the first place and taking it down is an important symbol for a new day dawning at Gettysburg," said Dennis Galvin, deputy director of the National Park Service.

The primary owner of the tower, D.C. businessman Thomas Ottenstein, declined comment, saying he had neither seen the lawsuit nor had time to consult with his lawyer.

Preservation groups praised Interior Secretary Bruce Babbitt for fulfilling his pledge to bring down the tower on his watch. Babbitt also has backed a Park Service plan to build a new visitor center at Gettysburg and restore the battlefield to its 1863 appearance.

"We're thrilled by this news," said Richard Moe, president of the National Trust for Historic Preservation, which helped lead the fight to remove the tower. "It's an abomination and should not have been built in the first place. We're strongly supportive of Secretary Babbitt."

O. James Lighthizer, president of the Civil War Preservation Trust, also praised the government's action and said "hopefully this will never happen again" at Gettysburg or other battlefields across the country.

"It's about time," said Eileen Woodford, northeast regional director of the National Parks and Conservation Association. "We'll finally have it out of the way."

The "complaint in condemnation," filed by U.S. Attorney David M. Barasch, said the tower property "is required for the proper administration, preservation and development" of the Gettysburg park and "for the use, benefit and enjoyment of the public."

Construction of the tower began in 1972 and quickly drew the opposition of then-Pennsylvania Gov. Milton Shapp. At one point, court proceedings stopped the tower's construction, at 178 feet. But in 1973, the Pennsylvania Supreme Court declined to halt the project. The following year, tower owners beat back a challenge in federal court.

The tower's location on private property effectively gave it immunity from federal land-use controls on the books at that time. A 1971 agreement between the Nixon administration and the tower developers also complicated legal arguments. The agreement let the Park Service swap land tracts with the developers so that the tower would not be built closer to the center of the battlefield.