Meanwhile, they've stored up plenty of tales to tell.
There's the one about the Confederate commander at Yorktown who, when he tried to draft slaves from local plantations to build defensive fortifications in 1862, was told by their owners to buzz off. Freis tells this as a parable of slave-owner selfishness, with the plantation gentry refusing to contribute to the defense of the very system that produced their wealth.
Asa Gordon, left, and Robert Freis at what was Gen. U.S. Grant's headquarters near Hopewell, Va., a site they'd like to include on a "Fight for Freedom" tour.
(Wayne Scarberry For The Washington Post)
There's the back-and-forth over the Confederates' use of captured black soldiers as laborers. "If you were black, you were a slave," Freis says of the basic rebel attitude. Hearing of the practice, Gen. Butler retaliated by putting captured Confederates to work digging a channel in the James River at a place called Dutch Gap, where they sometimes came under fire by Confederate artillery.
There's the grim saga of Ulysses S. Grant's siege of Petersburg, during which African American troops fought valiantly and -- at the Battle of the Crater, on July 30, 1864 -- figured in one of the most horrific fiascos of the war.
As dramatically rendered in the film "Cold Mountain," Union engineers tunneled under the Confederate lines and used barrels of gunpowder to blow a tremendous hole in them. What the filmmakers didn't explain was that black troops had been trained to take advantage of the gap the explosion created. At the last minute, the Union brass substituted untrained white troops, either because they didn't trust the blacks or because they feared political repercussions if they were perceived as having sent them to be slaughtered.
The untrained troops then botched the assault and the African Americans, who joined the fighting later, got slaughtered anyway. Some Confederates refused to grant them quarter when they tried to surrender. The biggest lesson of the Crater, Freis says, "is what a touchy political issue the presence and use of the United States Colored Troops was."
Finally, there are the two intense fights on Sept. 29, 1864, with which Freis and Gordon are planning to end their tour.
On the morning of that day, black troops stormed New Market Heights, a few miles southeast of Richmond. With great effort and heavy losses, they drove the Confederates off the fortified high ground. Fourteen African Americans won the Medal of Honor at New Market Heights, many for assuming command when white officers fell. Gordon has been active in efforts to better preserve the battlefield.
For some of those same men, however, the day ended extremely badly.
At Fort Gilmer, another Confederate stronghold a short march away, several attacks had already failed. Four companies of African American troops -- fewer than 200 in all, an absurdly small number given the strength of the defenses -- were ordered to continue the assault. The 120 or so who survived the murderous fire as they charged across the open ground wound up huddled in a ditch directly in front of the fort. The wall was so high, Gordon says, that men had to put their comrades on their backs to try to hoist them over "and then, as soon as their heads would rise above the parapet, they were mowed down."
They tried this more than once, in an exhibition of doomed heroism every bit as stunning as the larger-scale efforts of the Confederates in Pickett's Charge or the black troops at Fort Wagner. Yet the men who fought and died are history's stepchildren. "Nobody ever comes here," Freis says.
If he and Gordon have their way, that will change.