A July 9 Weekend article incorrectly stated that the Battle of Fort Stevens in 1864 was the only battle in U.S. history during which a president was present and under fire. President James Madison was on the battlefield at Bladensburg during the War of 1812. (Published 7/16/04)

On the afternoon of July 12, 1864, Union troops engaged in the defense of Fort Stevens on Washington's northern perimeter were startled to see a very tall, lanky man clamber up the earthen parapets of the fort and calmly survey the fighting. Indeed, curiosity had gotten the better of President Abraham Lincoln, who, together with his wife, Mary, and Maj. Gen. Horatio Wright of the 6th Corps, gained entry into the fort and stood watching while Confederate sharpshooters took aim at the defending Union forces.

Factual details of this presidential foray under Confederate fire are few, but this much is known: Sometime during the afternoon, a surgeon standing some three feet from the president was struck and killed. Wright reportedly entreated Lincoln to get down from the parapet and take cover, saying he could not be responsible for the safety of the commander in chief.

One colorful account has Lt. Col. Oliver Wendell Holmes (the future Supreme Court justice) ordering the president (whom he may not have recognized) to "get down, you fool!" Yet another story attributes those words to "Aunt" Elizabeth Thomas, a free black woman whose property had been largely confiscated for the construction of Fort Stevens.

What is certain is that Lincoln eventually did come down -- albeit reluctantly -- from the fort's forward parapet, and the Battle of Fort Stevens continued in earnest. By nightfall, the conflict had claimed nearly 900 casualties, and the only Confederate action of the Civil War against the U.S. capital was over.

Today, Fort Stevens still has the distinction of being the only battle in American history during which a president was present and under fire while in office.

On Saturday, Fort Stevens (now part of Rock Creek Park) will commemorate the 140th anniversary of the battle with a number of tours and living history programs at the partially restored, three-acre site -- within the boundaries of the District at 13th and Quackenbos streets, just west of busy Georgia Avenue in Northwest. A bronze plaque on a large boulder signifies the spot where Lincoln stood, and the imposing earthworks and several cannons help convey the sense of what the once heavily fortified stronghold must have looked like in July 1864.

A stop at Fort Stevens would not be complete without visiting the nearby Battleground National Cemetery, a half-mile north of the fort, on Georgia Avenue. The tiny cemetery, sandwiched between several apartment buildings, is the final resting spot for 41 Union soldiers killed at the Battle of Fort Stevens. Several monuments and a circle of diminutive marble headstones are a poignant reminder of the time 140 years ago when "enemy" troops came within five miles of the Capitol -- only to lose the war the next year.

FORT STEVENS -- Rock Creek Park, 13th and Quackenbos streets NW. www.nps.gov/rocr/schedule/july04.htm. Parking at Fort Stevens is limited; visitors can park at the Rock Creek Park Nature Center and take shuttle buses to Fort Stevens and Battleground National Cemetery. Buses will leave every hour on the half-hour on Saturday, starting at 9:30 a.m., with the last bus leaving the nature center at 4:30 p.m. All events are free.

Saturday -- The 1st Connecticut 2nd Regiment Heavy Artillery Civil War Encampment from 10 to 4. Craft tent for children with Civil War-era games and activities from 10 to 4. Dramatic presentation of "The Story of Ms. Thomas" from 10:30 to 10:45. Lecture, performance, demonstration by the Wildcat Regimental Band from 10:45 to noon. Ranger-led discussion of the Battle of Fort Stevens from noon to 1. Performance by a Lincoln reenactor from 2 to 3. Wildcat Regimental Band from 3 to 4.

* At Battleground National Cemetery (6625 Georgia Ave. NW) -- Ranger-led tours of the cemetery from 10 to 4.

* At the Rock Creek Park Nature Center (5200 Glover Rd. NW, off Military Road. 202-895-6070.) -- "Night Sky to Freedom" planetarium program from 1 to 1:30 and from 4 to 5.

-- Patricia Weil Coates

Lora Williams of the National Park Service is in charge of the commemorative events at Fort Stevens in Rock Creek Park.