Scott Sedar, left, as Abraham Lincoln, greets members of the 61st Pennsylvania company on July 12 as Fort Stevens celebrates the 150th anniversary of the Civil war battle fought there. (Bill O'Leary/The Washington Post)

“No man can be seen in the brush, but every square rod of it is alive with action. We see the smoke, we hear the report of musketry. . . . Our city is in a crisis circumstance.”

Actor Scott Sedar gestures toward the area he’s describing: a steep hill topped with half-buried wooden fortifications and a large radio tower overhead. Kids wearing sneakers and T-shirts weave in and out among hoop-skirted women holding parasols, and a few yards away, half a dozen men in blue woolen uniforms march in time to a sergeant’s orders. Onlookers snap photos. A tinny flute playing “Yankee Doodle” competes with the sounds of traffic from nearby 13th and Quackenbos streets in Northwest Washington.

Sedar, who introduces himself as President Abraham Lincoln, peers down at his audience from beneath a black top hat.

“You can see why Mrs. Lincoln did not want me here,” he confides.

Sedar’s pretense seems almost comical on this quiet July afternoon — so different from the carnage that took place here exactly 150 years ago. But for the 200 National Parks Service employees and volunteers who organized Saturday’s sesquicentennial celebration of the Battle of Fort Stevens, the war is still strikingly present.

Visitors clamber over the battlements on July 12 as Fort Stevens celebrates the 150th anniversary of the Civil war battle fought there. (Bill O'Leary/The Washington Post)

“Any time you can come up and be on hallowed ground, it’s always special,” says reenactor David Welker. “It connects you to the men who fought here, and the events.”

Even without closing his eyes, Welker can picture the battle scene: the rounds flying and guns firing, the chaos and fear.

“We know how it turns out; they didn’t,” Welker says. “So there was a lot of tension and uncertainty.”

Rightfully so: Though Fort Stevens is a little-known memorial to a little-known battle of the Civil War, it was actually the closest the Confederate Army ever came to taking control of Washington.

On the afternoon of July 11, 1864, members of the Union’s Veteran Reserve Corps — wounded soldiers who were deemed fit to defend the capital — held off 10,000 soldiers led by Confederate General Jubal Early until reinforcements could arrive. Had they failed, Early might have marched on to what was then the City of Washington.

“And then, who knows what could have happened, how the war could have gone differently,” says Bernie Silber, a D.C. lawyer who moonlights as a Civil War historian and reenactor.

Siler grew up just a block away from this spot, and he recalls coming to the park to wrestle with his friends and stage pretend battles on the ramparts. But he wasn’t aware of the fort’s significance until he was 14: A piano teacher assigned him the song, “Battle Cry of Freedom,” and in researching the piece, he discovered that it was sung by soldiers during the battle here.

Like Welker and Silber, most of the volunteers have some personal reason for their dedication to Fort Stevens. The park isn’t an ideal spot for a commemorative ceremony — it’s small, and Parks Service rules prohibit full reenactments on former battle grounds — so their living history demonstrations are limited to dressing in period clothing and explaining history to visitors. On top of that, Alexandria’s Fort Ward is also holding a sesquicentennial celebration this weekend, one that offers far more opportunities to get into character.

This means that the reenactors at Fort Stevens are true fans, the ones with long-standing connections to the spot who want an opportunity to walk the ground where the actual battle happened.

“The Civil War happened right here,” says Bryan Cheesboro, who also grew up a few blocks from the fort. “It means everything to me to be here and not” at Fort Ward.

Cheesboro spent three months recruiting reenactors for the event and was dressed as a civilian war volunteer, wearing a white cotton shirt under a blue wool vest and carrying a replica hunting rifle.

“Coming to this and seeing all these people here . . . it’s like coming home,” he said.

So many of the volunteers speak about Fort Stevens with that same passion. For all its obscurity, the grassy square in the Brightwood neighborhood inspires a peculiar degree of love.

Kym Elder, the NPS ranger who organized the commemoration, was grinning for nearly the entire duration of the six-hour event.

“I was almost in tears at one point, that this has all come to fruition,” she said.

Though Silber, too, relishes the crowd that has gathered for the sesquicentennial, he also likes to visit the fort on quieter days. He often comes to sit on the hill, feeling “the calm and the energy” and letting the battle come alive in his imagination.

But not too alive.

“When I go home into my bedroom, I’m right at the level where bullets would have been flying,” he says. “And my imagination stops there.”