WERE IT MERELY that Joe Louis was the best heavyweight boxer of all time, those of us who are not nuts about boxing might leave appreciations of the man to the ringside historians. But Joe Louis, who died Sunday in Las Vegas at the age 66, was not only the best in his business, but also an American folk hero at a time when these ranks were not exactly bursting with Americans of color. The enormous appeal of the "Brown Bomber" was as a symbol of uncomplicated physical and moral strength, honesty and compassion.

From the humble, cotton-field country beginnings of Joseph Louis Barrow in Alabama through the humbling, pathetic final years of a sick man whose fortunes had disappeared, there was always a special dignity to him. Though many of us winced when this great champion was reduced to odd jobs in a sad effort to recover from too many years of financial naivete, those misfortunes never really detracted from the measure of this courageous man.

Today's young Americans may not readily identify with the popularity and respect that Joe Louis enjoyed, since he was not a man of television-age charisma; he was not articulate, nor was he one to throw himself visibly into marches or other demonstrations. "Some folks shout some holler, some march, and some don't," he once said. "They do it their way, I do it mine."

His way, as an article in Ebony magazine by Chester Higgins noted, was to give inspiration to "down-trodden and despired people. When Joe Louis fought, blacks in ghettos across the land were indoors glued to their radios, and when Louis won, as he nearly always did, they hit the streets . . . in celebration. For Joe's victory was their victory, a means of striking back.

. . . Louis was the black Atlas on whose broad shoulders blacks were lifted." And because this skill and popularity crossed the heavy color lines of the day so spectacularly, Joe Louis won much more than 68 out of 71 fights -- he won a special place among the great Americans of his time.