FOR THE past few weeks, people have been looking back over the 50 years since the great March on Washington and pondering how much or little has been done to realize the vision set forth at the Lincoln Memorial that day by Martin Luther King Jr. Sometimes, though, it’s worth looking in the other direction from Aug. 28, 1963, to the half-century before it, which began with a signal event in the summer of 1913.

More than 50,000 old men who had once fought the war that ended slavery gathered at Gettysburg to commemorate some of the bloodiest days in U.S. history. The large majority were Union veterans, but a sizable contingent came from the former Confederate states. The men fraternized, commiserated and, in general, buried old grudges in a coming-together that was touching, but also deeply tragic. It was tragic because this and other events of reconciliation that marked the era showed that the cause of complete emancipation of black Americans was being abandoned — not just freedom from slavery but also the right to vote, to work and achieve to the best of one’s abilities, to prosper and be a full, respected member of society.

Reunion between North and South was to come at the cost of the country’s highest ideals. The hopes of presidents such as Ulysses S. Grant and the martyred James Garfield for advancement of America’s “freedmen” were forgotten. Under a succession of presidents in the first half of the 20th century, whether they were “progressive” Democrats or conservative Republicans, the bizarre racial codes of the South became entrenched to varying degrees in much of the country, bolstered by long-serving and powerful Southern senators who held many of the levers of power and stymied any legislation that bore the slightest chance of advancing civil rights — even bills meant to curb the lynchings that disgraced America.

The federal government, like much of the country, went backward in its employment practices. As America’s entry into World War II neared and manpower suddenly became an urgent priority, only a tiny portion of African Americans were contributing what they were capable of or were sufficiently prepared to do so. Respected figures in high positions in government and industry spoke openly of their disinclination to hire blacks and, quite often, women as well. The historian Maury Klein relates that the War Department had only 600 blacks among its 13,000 positions. He tells of one light-skinned black man, applying for a job as a radio engineer, who so impressed defense officials that they offered him a better post, only to withdraw it when he responded to a question about his nationality by saying, “I am an American Negro.” The president of a major aviation firm was quoted as saying, “Negroes will be considered only as janitors and in other similar capacities. . . . It is the company policy not to employ them as mechanics and aircraft workers.”

This could not last. It couldn’t survive the demands of war, which brought millions of African Americans into factories and firms and the armed forces — and, for a growing number of people, it couldn’t be squared with American values. Then came television, carrying into millions of homes images of a black woman arrested for refusing to give up her seat on a bus, of a young preacher leading a mass protest movement and, 50 years ago today, of more than 200,000 people, blacks and whites, gathering peacefully in the nation’s capital to demonstrate for equality.

Aug. 28, 1963, was a symbolic moment, if not a turning point. While racial bigotry was not dead, it was no longer respectable, was not something that could be openly proclaimed by Cabinet officers, corporate leaders, even presidents of the United States. Its true shamefulness and cruelty became part of the national consciousness that day, expressed by King in forceful declarations and demands for equality, in biblical imagery and oratory, but also in simple images, none perhaps more enduring and meaningful to the great audience he sought to reach than that vision of children someday playing together with not a thought to the color of their skin.