Reenactors with the 54th Regiment Massachusetts Volunteer Infantry fire muskets during ceremonies to honor the anniversary of the historic 1863 Civil War battle of Battery Wagner held on Morris Island. (Paul Zoeller/FOR WASHINGTON POST)

In October 1850, an outraged freeman named Joshua Bowen Smith stood up and brandished a knife before a crowd of fellow black residents of Boston. They were gathered to discuss their fears about the new Fugitive Slave Act, the decree that empowered slave agents to come north and seize any black person on mere suspicion of being escaped chattel. The law threatened even the most secure members of African American communities such as Smith, a successful caterer. Resist, Smith urged the crowd. Buy Colt revolvers and choose death rather than be taken. “There is no peace,” he said. “Show yourself a man. If liberty is not worth fighting for, it’s not worth having.”

Yet it would be more than a decade before blacks were allowed to openly fight for their lives. Two years into the Civil War, blacks could still not legally handle muskets and wear uniforms to defend themselves and their country. For freemen and slaves alike, half the battle of their Civil War would be simply struggling for the right to enter the battle at all. Frederick Douglass was so frustrated by President Abraham Lincoln’s slowness in recruiting and arming willing blacks that he accused Washington of “fighting the Rebels with one hand.”

In May 1862, two young white officers named R. Morris Copeland and Robert Gould Shaw went to Secretary of War Edwin Stanton with a proposal to raise a black regiment from Massachusetts. Stanton refused, and when Copeland wrote a scathing editorial blaming Stanton for inadequate troop levels, he was cashiered. In the spring of 1862, a deputation of Western gentlemen visited Lincoln and offered to raise two regiments of black soldiers from the state of Indiana. The president courteously but firmly declined the offer, telling them he feared that “to arm the negroes would turn 50,000 bayonets from the loyal Border states against us that were for us.”

But by late summer, the administration was finally moving toward inducting blacks into the service. What changed? A combination of political expediency and battlefield urgency.

At this point, there was less danger of backlash from the border states, which by then were under Lincoln’s control. A series of embarrassing military reversals had created mounting public pressure, while commanders in the field were crying out for men. While white enlistments were decreasing, slaves were pouring into the Union lines.

The focus of the war moves west

On July 17, 1862, Congress passed the Second Confiscation and Militia acts, freeing slaves whose masters served the Confederacy and authorizing Lincoln to induct blacks for any purpose he saw fit. That August, Stanton quietly ordered Gen. Rufus Saxton to begin forming a trial unit of 5,000 volunteers made up of South Carolina slaves. Then, on Jan. 1, 1863, Lincoln released his Emancipation Proclamation; contained in its broad sweep was a short but crucial sentence that authorized the military enrollment of blacks: “Such persons of suitable condition will be received into the armed service of the United States.”

Just a few days later, on Jan. 10, 1863, the 1st Regiment of South Carolina Volunteers held a celebration of the Emancipation Proclamation in their camp, during which Saxton presented them with their first regimental flag. Accepting the flag was a black sergeant named Prince Rivers, who addressed the men. “Brothers! Soldiers!” he called out. “One request I make to you now, for the first and last time. When, on the battlefield, you see me fall under this flag, bury me, hide me, but let this flag still float before the eyes of all.”

As Rivers finished speaking, spontaneously the men began to sing. Their unit commander, Col. Thomas Wentworth Higginson, was at first startled, then was overcome as he realized what song they were singing. It was “My Country, ’Tis of Thee.” As the voices of the freedmen rose, Higginson and other white officers wept. Higginson noted that he had never heard them sing the song before, because “they never could sing it, never felt they had a right to, never felt they had any country until today.”

Yet deep skepticism about the usefulness of black troops persisted among white officers. For much of their war, African American soldiers would earn lower wages for tougher duty — $7 a month compared with the $10 paid to white soldiers. They would perform some of the dirtiest and most backbreaking work of the war, digging trenches and building breastworks while white men of equal rank idled. Some white soldiers tried to impress them as menial servants. According to the New York Tribune in May 1863, whites “have generally become willing that they should fight, but the great majority have no faith that they will really do so.”

The troops in South Carolina were determined to prove their worth as soldiers rather than ditch diggers. Higginson hurried his men into action, eager to show they could and would fight. At the end of January they went on a two-week marauding expedition along the Georgia-Florida line and won a small but sharp skirmish over mounted Confederates at a place called Township Landing. Higginson was leading them through thick piney woods at midnight when they heard charging hooves. The men held steady — and emptied 13 rebel saddles with their first fusillade. The victory made national news, as did the fact that they came home with significant stores of captured iron and wood and seven rebel prisoners. “Braver men never lived,” Higginson wrote. “It was their demeanor under arms that shamed the nation into recognizing them as men.”

It wasn’t until the spring and summer of 1863 that black troops would win larger acceptance, and it came at the price of heavy casualties in three major battles. On May 27, 1863, at Port Hudson, La., two African American units, the First and Third Louisianans, stormed a heavily fortified Confederate stronghold in a hail of fire and suffered 200 casualties. Their conspicuous bravery impressed Union Gen. Nathaniel Banks, who reported, “The severe test to which they were subjected, and the determined manner in which they encountered the enemy leaves upon my mind no doubt of their ultimate success.”

Just two weeks later, on June 7, 1863, inexperienced black troops on what was supposed to be rear-guard garrison duty found themselves in a maelstrom at Milliken’s Bend, Miss. The bend was a supply depot and jumping-off point for Gen. Ulysses S. Grant’s drive against Vicksburg, 15 miles down the river. Confederates seeking to cut Grant’s supply line and distract him launched a surprise attack on the depot, which he had left defended largely by African Americans who had been soldiers for only a month, from the 9th Louisiana Infantry, the 1st Mississippi Infantry, and the 13th Louisiana Infantry.

Trapped in a small area under crossfire, the Union troops fought off rebels with bayonets and rifle butts until their backs were pressed against the Mississippi riverbank. Their line held despite terrible casualties — in the 9th Louisiana, 45 percent of the men were either killed immediately or fatally wounded — until Union gunboats finally relieved them. Even the Confederate commander, Gen. Henry E. McCullough, was moved to grudging respect, observing that his charge “was resisted by the negro portion of the enemy’s force with considerable obstinacy” while many white troops did not behave as admirably under fire.

Milliken’s Bend convinced the most important constituency that black soldiers had valor: white officers. Assistant Secretary of War Charles A. Dana wrote that Milliken’s Bend “completely revolutionized the sentiment of the army with regard to the employment of negro troops.”

This was the context and frame into which the famed 54th Massachusetts Regiment marched a little more than a month later, when it spearheaded the attack on Fort Wagner the night of July 18, 1863. The unit, raised largely in Boston and numbering among its members the sons of Frederick Douglass, was highly motivated to win not just honor but also equal pay and basic rights. “Once let the black man get upon his person the brass letter, U.S., let him get an eagle on his button, and a musket on his shoulder and bullets in his pocket, there is no power on earth that can deny he has earned the right to citizenship,” Douglass declared. His sons Lewis Douglass, 20, and Charles, 18, had been among the first to sign up.

The major events at Fort Wagner were famously dramatized in the film “Glory.” Less well known are the smaller details, such as the fact that the 54th was half dead with fatigue before it ever began the charge, with nothing to eat for two days but crackers and coffee, while marching through swamps and sleeping without tents in a pouring rain. They arrived at the attack point with just five minutes or so to rest before forming up to lead the charge. “They looked weary and worn,” said a witness.

To reach Fort Wagner, the heavily defended redoubt near Charleston, S.C., they had to cross 600 yards of sand, then a ditch filled with three feet of water, with no cover. Grapeshot tore through them with 200 yards still to go. Yet somehow they made it to the ditch and up the parapet.

Carrying the colors was William Carney, sergeant of Company C. According to Carney’s own account as well as those of witnesses, he grabbed the flag when the color sergeant was shot, then pressed forward with it, staying near Robert Gould Shaw, the same white officer who had petitioned Stanton for black recruitment in 1862. Shaw cried, “Onward, boys!” as he led his men over the ditch. Carney struggled to the top of the parapet, where he was struck instantly by fire, taking bullets in the thigh and head — yet managed to plant the flag as he fell on his knees, and keep it in place. He lay down on the slope, trying to get as much cover as possible as the battle raged for about 25 more minutes, before the regiment “melted away under the enemy’s fire, their bodies falling down the slope and into the ditch.” Among those bodies was Shaw’s. As the force retreated, Carney somehow dragged himself away on his knees — still holding the flag.

Carney was clutching it when he entered the field hospital, to the cheers of his fellow soldiers. “Boys, the old flag never touched the ground,” he said. He would be awarded the Medal of Honor.

The 54th Massachusetts became the most celebrated black regiment, but it represented just 600 men out of the 180,000 African Americans who fought for the Union. Of those, 37,300 would die, and more than 20 would be awarded the Medal of Honor.

In 1865, when the fighting was over, another emotionally fraught meeting took place in Boston. This time the subject was a suitable memorial to Shaw and the 54th Massachusetts, which would eventually result in the famed sculpture by Augustus St. Gaudens in Boston Common. The meeting was called by a now-aging black merchant, one who had practically bankrupted himself in helping to raise, feed and equip black troops during the war. His name was Joshua Bowen Smith.