Their fighting in the 1863 battles at Port Hudson, Milliken's Bend and Fort Wagner proved the mettle of the United States Colored Troops.
Often overlooked, said Anthony Gibbs, is how their sacrifice helped win the day for the 14th Amendment to the Constitution, the amendment that forever changed the nation with its equal protection clause.
Gibbs will bring the story of the 200,000 black Civil War soldiers to life during a first-person presentation at 7 p.m. Tuesday in the Heritage Center of Clark County's Crabill Discovery Hall.
Admission is free thanks to sponsorship from the Ohio Humanities Council, an affiliate of the National Endowment of the Humanities.
An Ohio State University history graduate who works at the Ohio Historical Society and is founder of Black Historic Impressions, Gibbs said black men sought to fight for their freedom as soon as the war started.
"There were a number who fought even before the Emancipation Proclamation," he said.
For larger political and military purposes, "Lincoln didn't want them to be officially soldiers," Gibbs said.
The president famously rescinded field commanders' decision to emancipate blacks in the areas they controlled. Still, many effectively freed blacks "would just follow the Union troops" as they advanced, providing what help they could, Gibbs said.
When Lincoln eventually signed the proclamation Jan. 1, 1863, Gibbs said, its primary purpose was for the military.
"Most historians agree it was a war measure," he said.
But it also had political ends.
"It was particularly (crafted) to give the Union an edge, to make the war more noble," Gibbs said.
Specifically, it discouraged European nations, particularly cotton-hungry Great Britain, from recognizing the Confederacy. Having ended slavery in their own countries, the European nations did not want to align with the side perpetuating what was called America's "peculiar institution."
"There was definitely a political reason for doing that," Gibbs said.
The measure that was so successful in foreign policy was more controversial at home.
Riots broke out in the North, including in New York, where troops were sent to restore order after blacks were killed and attacked on the streets.
Lincoln "got all kinds of criticism," Gibbs said. Because of that, even after the president brought black soldiers into the Army, he kept them out of combat.
"Initially these troops built up fortifications and were digging trenches," Gibbs said, the kind of work done by the freed slaves who tagged along with the Union Armies.
Because he knew all eyes would be on the first black troops in combat, Gibbs said, "Abraham Lincoln wanted to make sure they got good training," and appointed some of the most qualified white officers for the work.
"Of course, many of these officers didn't want the positions," Gibbs said. But while doing what they were ordered to do, "they learned to respect these men."
Black Ohioans, including Springfielder Charles Gammon, headed east to join the 54th and 56th Massachusetts regiments, while others trained with the 127th Ohio Volunteer Infantry, which mustered at Delaware, Ohio, and later became the 5th United States Colored Troops.
Gibbs, who considers Lincoln "a level, even-minded person," said the president's changed attitudes to slavery and blacks is rightly portrayed in the movie "Lincoln," which focused on passage of the 13th Amendment and the end of slavery.
Once black troops had died in the cause, Lincoln refused to consider negotiating an end to the war by bringing back slavery, famously saying he "should be damned in time and eternity" if he had.
Gibbs said the 14th Amendment, adopted in 1868, "was especially created because these men gave their lives to save the Union."
In the record of the debate on the issue, "that was a major piece," he said.
For the outcome of the debate "it was definitely important that these men fought," he said. "In the highest political realm, they were respected for what they did."
Without an attempt at irony, Gibbs said that if Reconstruction "did not go South," history could have been different.
The denial of full equality to blacks who fought in the Civil War was experienced again by black soldiers returning from the Spanish-American War, World War I and II, Vietnam and beyond, something Gibbs said is evidence of how slavery "polluted" the American political system.
While satisfying the hunger of the cotton gin and the economy it powered, slavery "helped to define race relations in this country," created the economic need to justify inequality and even today influences people who "continue to push these attitudes and beliefs" in an attempt to ennoble either the cause of slavery or those who fought to perpetuate it.
Despite the nation's failure to uphold equality during Reconstruction, the principle "was in the books," stored safely away in the 14th Amendment.
There it waited for those who fought for civil rights a century after the Civil War.