THIRTY YEARS AGO today, there was a story on the front page of The Post from Richmond that said Virginia's governor had signed a bill calling a constitutional convention to enable the state to subsidize private, all-white schools. Far back in the paper, another report from Richmond said state senator Harry F. Byrd Jr. was applauded when he rose to commend a state appellate court for backing Virginia's annulment of a marriage between a white woman and a Chinese man. And in the classifieds there was an ad in the houses-for-sale section that began: "COLORED . . . Brand new brick ramblers. . . . "

All pretty routine for those days. No wonder some young children, learning for the first time this past week about Martin Luther King Jr. and the American civil rights revolution, returned home from school to ask their parents, "Was it really like that?" We all can use a little reminding that it was, in fact, like that not too long ago. There were segregated schools in the suburbs of this national capital, separate water fountains and restrooms, and lunch counters where a black construction worker had to stand and order his food to take out. Schoolchildren were bused across a large suburban county to the nearest black school and, in the winter months, returned home after dark. The usefulness of such a reminder was one of the arguments we made in favor of creating this national holiday in honor of Dr. King's birthday when the proposal was before Congress in 1983.

Thirty years ago the revolution in consciousness that Dr. King helped bring about had barely begun. Since then, it has been, if not completed in the hearts and minds of every citizen, at least institutionalized, and so widely accepted as to make the customs spawned by slavery and segregation seem like curiosities from another age.

But it was a revolution that did more than bring an end to the legal segregation of black Americans. As a southern writer pointed out on the opposite page last week, it opened up the South to economic development, and thus probably benefited southern whites more than blacks. Moreover, throughout the nation it fostered a state of mind that was conducive to change and to agitation. Other racial minorities, organizations of women, the elderly and the poor -- to name a few -- took their cue from the civil rights movement, adopting its methods and its spirit (which is not to say that all the causes they espoused were always equally noble). Fortunately the man who had set the tone and established that spirit was one who was steadfast in his devotion to nonviolent protest and had faith that it could transform a free society.

This country will be a long time working out the changes set in motion by the civil rights movement and deciding what the next steps are to be. But this holiday signifies that at least one basic principle -- equality before the law -- is now accepted unquestioningly by all but a tiny few, and we can move on from there.