John W. Rusk is more at ease portraying Uncle Sam than President Lincoln. He doesn't get a chance to do Lincoln all that often, and everyone, it seems, needs an Uncle Sam.

Uncle Sam is needed at parades, at school to give talks on patriotism and the flag, even on television to plug U.S. savings bonds, he says, but Lincoln is in lesser demand.

Still, Rusk's Lincoln didn't seem so rusty yesterday as he reviewed the troops at the 10th annual reenactment of the Battle of Fort Stevens, a startlingly realistic hour of cannon and musket fire.

The Battle of Fort Stevens took place on July 12, 1864, not too far from the present site of Walter Reed Army Medical Center in Washington, but is reenacted in Alexandria near the Fort Ward museum.

The battle was more of a skirmish by Civil War standards. The dead numbered fewer than one hundred--nothing compared with the tens of thousands who fell in the Battles of Antietam and Gettysburg--and the number of troops involved was minimal.

But the Battle of Fort Stevens is notable for two things:

It was as close as the Confederate Army ever got to the city of Washington; and it was the only time an American president in office was ever fired on by enemy troops, according to the staff at Fort Ward.

That's where Lincoln--and Rusk--came in. Lincoln journeyed from Washington to see the battle, and during a lull in the fighting mounted the parapet to get a better view of the fighting.

Confederate sharpshooters opened fire on the president, and an aide, reputed to be the young Oliver Wendell Holmes, shouted, "Get down, you damn fool!"

"I see you know how to address civilians," Lincoln is said to have responded.

For his part, the 75-year-old Rusk, clad in black stovepipe hat and long black coat and sporting a bogus beard, dutifully scrambled atop the parapet, then down again when the Confederate snipers' rifles started to crack.

Mission accomplished, Rusk took his leave.

The battle then resumed, history having been made, with Confederate Gen. Jubal A. Early--"Old Jubilee"--pressing his futile attack.

To the crowd of several thousand that ringed the battlefield, the reenactment was spectacularly true to life.

"You'd think this was the real thing," said Kerry Filburn of Bethesda. "One of them was firing toward this way and I didn't like that at all."

Nearly three hundred troops on the battlefield fought it out for an hour in the midafternoon heat. The din of their crackling rifles and crashing cannon fire sent more than a few small children wailing into their mothers' arms.

The troops, in "reactivated" Civil War units from various mid-Atlantic states were faithful to the event to the last detail. They were a ragtag crew, as the actual Union and Confederate armies were said to be ("You smell the army before you see it," was a popular saying of the day), and all wore the woolen blue or gray jackets that made fighting in the summer sun so unbearable.

The muskets, canteens, shirts and other gear were also either authentic or close replicas.

"I'm the ultimate Civil War hobbyist," said Bruce A. Stacking of Manassas, who fought on the Union side yesterday as his ancestors did more than a century ago. "You can read about it or write about it or study it--I go out there and do it."

Stacking, a colonel in the First Delaware Volunteers yesterday and most summer weekends, and a ranger at the Washington Monument the rest of the time, has been doing various Civil War battle reenactments around the East Coast for 11 years.

"I take it very seriously," he said. "The two sides are like boxers who are the best of friends until they get into the ring--and then they really go at it."