Six weeks into quarantine, I was flailing. My wife was pregnant and in the midst of terrible morning sickness, our 4-year-old son was sick of all the activities I’d devised outside our D.C. apartment building, and I was sick of our 900-square-foot apartment. He and I set out one day to hike in Rock Creek Park, 1,700 acres of wilderness that run up the spine of the northwest quadrant of the city. Walking up a hill — slowly, because he’s 4 — we stumbled upon the old Civil War earthworks at Fort DeRussy, and it hit me. We now had a quarantine mission. We would visit all the Civil War defenses of the Washington region.

I had no idea how relevant our mission would soon become.

 After the Union lost the first major battle of the war at Bull Run in 1861, George McClellan took command of the Union army and beefed up the capital’s system of defenses, until they numbered 68 forts and 93 batteries. They ringed the city, concentrated around the expected routes of a Confederate attack. They defended key junctions and bridges — such as Chain Bridge, a vital link for Union operations in northern Virginia — and protected the capital from a naval attack up the Potomac. Most have been reduced to historical markers, but a handful are preserved by the National Park Service and by the city of Alexandria and Arlington County. You can find a list on Alexandria’s and Arlington’s parks department websites.

 So, we set off, checking off a couple of forts per week. We came with a Frisbee in tow in the event that, as is the case in several spots, there was no evidence of a fort at all, nor replica cannons, nor anything to go “find.” I am a historian — although I study North Africa — so our new project held natural appeal. But the 4-year-old, as children are wont to do, had questions. Who was fighting? Were they using guns or “blasters”? Were these piles of dirt really “forts”?

When I was a kid myself, I fell hard for the Civil War. I pored over books and battle maps, I implored my parents to take me to battlefields, I re-created Little Round Top in my sandbox. As my son and I toured the forts, I was struck about how little our official memory and collective processing of the war has changed in 30 years. We’re still drawn to battlefields and monuments for the drama and bravery, but those sites tend to remove ideology and social conditions from the war. They teach us about generals, and about Minié balls and Parrott guns, but less about the motivations of the people actually fighting or the communities around them.

 I recognize it now as a bizarre sort of privilege, to focus so much on the battles themselves but so little on what came before and after — especially how the reunified nation failed to address the fundamental racism at the heart of the Confederacy. As Black Lives Matter-related protests gathered momentum in June, they brought Civil War memory back into the spotlight. Our fort tours changed, too, from a pandemic diversion to a way to help my son (and myself) put the war into context, to connect it to the ongoing struggle for justice we were witnessing in our own city.

Unfortunately, the preservation of some of Washington’s defenses lacks such context. The marker for Battery Rodgers in Alexandria, for example, does not mention the war at all, only that the battery defended against “enemy ships” and was commissioned from 1863 to 1867. Many of the signposts administered by Arlington do not even gesture toward the war. No “Union,” no “Confederacy,” and no “treason” or “slavery,” either. They are simply the “Historical Sites of the Defenses of Washington.” Fort Ethan Allen — Arlington’s best-preserved fort — has several displays on defensive artillery tactics but little else. By contrast, Alexandria’s most interesting site, Fort Ward on Braddock Road, has extensive signage on the free Black community that grew up nearby (called “the Fort”) and how it helped support the military effort.

But having a 4-year-old companion does not allow much time for sign reading. One sticky June morning, we made our way to Fort Foote, five miles south of the city in Prince George’s County, Md. We wound our way through a quiet neighborhood, then walked past picnic shelters and into a dense forest. Suddenly, the contours of a fort revealed themselves as we snaked between vines and the faded earthworks. There, looming ahead, were the two biggest cannons I’d ever seen.

 If you drag a 4-year-old to a bunch of dirt piles and are trying to convince him they’re forts, you need cannons. They are the coin of the realm. Fort Foote’s cannons are the original Rodman smoothbores, and they are massive. They sit on a high bluff above the Potomac — with great views of Alexandria on the opposite shore — commanding the river. I envisioned Confederate ships steaming upriver, and these guns pounding them. I tried to explain the idea. “But Daddy,” he asked, “would they be shooting bullets or lasers?”

Not all the fort sites are so exciting. Fort Bunker Hill, east of the Brookland neighborhood of Washington, is basically a square block of trees, although we did see a couple of pileated woodpeckers. Fort Bayard once guarded the west side of the city; now it’s occupied by strollers and an old playground. Fort Reno offers nice views, but the Civil War traces are gone, and the greatest draw for a kid is searching for the seal marking the District’s highest point.

The most famous of the defenses is Fort Stevens on Georgia Avenue in Northwest Washington. Just a small square block, the ramparts have been restored (with cannons!), and a plaque marks where President Abraham Lincoln was nearly shot during the only Confederate attack on the capital, in July 1864. He remains the lone sitting president to be fired upon by enemy troops.

 In early June, about halfway through our tour, protests broke out across the country, demanding justice for George Floyd, Breonna Taylor and other Black American victims of police violence. We joined other families in a march down Wisconsin Avenue to  a Black Lives Matter rally on the Washington National Cathedral steps. It was a powerful scene, made more so for me by the sight of my son, masked, listening to speeches and songs and somehow remaining quiet for the entire eight minutes and 46 seconds of silence. When it came time to chant, he was in full voice. Then he whispered, “Why was the South fighting against the North, Daddy?” I reminded him about slavery. I told him that was why we had come, because the South had lost the war, but Black people still weren’t equally treated.

 The next day, we were hunting for forts again on the east side of the Anacostia River, in a historically Black part of the city. There, Fort Circle Park’s hiker-biker trail links six NPS fort sites. Fort Dupont’s earthworks are tucked in the woods near Alabama Avenue, but the other sites varied in their accessibility and suffer from lack of  upkeep. Fort Ricketts, across from the Smithsonian Anacostia Community Museum, was covered in vines too thick to even glimpse the earthworks. The trail toward Fort Stanton narrowed to a few inches, and the sign was obscured by 10 feet of high weeds. Numerous groups have floated ideas for improving the smaller fort parks here, but all lack funding. Though these are not marginal spaces in the fight for freedom and equality, they feel that way to visitors today.

Of the 68 sites, three discussed above are must-sees (Fort Stevens, Fort Foote and Fort Ward), and four others are worth a visit (Fort Ethan Allen, Fort Dupont and Fort DeRussy, plus the 19-acre Fort C.F. Smith, which contains the best-preserved earthworks in Arlington, as well as a visitor center, trails and gardens). Anyone heading to Fort Stevens will want to tack on Battlefield National Cemetery, where 41 of the 59 Union soldiers who died in the fighting are buried.

 As we completed our mission, Confederate monuments across the country started to come down, and I began to wish more of these Union forts were still standing. I thought of the incomplete story that Washington’s forts tell, especially when some remain prominent, some languish and some are gone completely — and many gloss over the complicated outcomes of the war. They demand to be seen as a whole: Sixty-eight forts established to defend a city of just 75,000 residents from an invading army intent on preserving the institution of slavery. I looked at my son, who spent much of our mission brandishing sticks like swords, and held on to a bit of hope that he and his peers might learn about the war for what it was rather than what we wished it had been.

Correction: A previous version of this article referred to Arlington as a city; it is a county.

Historian Graham H. Cornwell is the assistant dean for research at the Elliott School of International Affairs at George Washington University. He lives in D.C. with his wife, Judy, and his son, Gibson. On Twitter: @ghcornwell.