ONLY THE OCTOGENARIANS among us can remember personally Roger Baldwin's earliest struggles -- during World War I -- to protect the constitutional rights of radicals, labor organizers, pacifists and other folk unpopular at the time. The phrase "civil liberties," much less the reality, then remained virtually unknown. But the bold challenge by Mr. Baldwin and a small number of like-minded libertarians to the repressive actions of the Wilson administration both during and after the period of U.S. involvement in World War I (1917-1920) established a credible foundation for strengthening the protected rights of dissenters since that time.

Although Roger Baldwin, who died this week at 97, became best known subsequently as the founder (in 1920) of the American Civil Liberties Union and as its director for three decades, his personal influence far exceeded the reach of that organization alone. Through more than a half-century of notable courtroom and political campaigns to stretch the prevailing conception of free expression, Mr. Baldwin held to his continuing faith that "all great struggles for liberty have been conducted against the forces opposed to change . . . detemined to protect the status quo and the privileges of its most powerful elements."

At its best, the ACLU has followed to a fault his commitment to defending those of every political persuasion and pleading in their right to raise "all matters of public concern . . . without interference," whether from government or from intolerant majorities. From its beginnings, the ACLU's unfettered defense of free speech at the nation's extremities made that group ombudsman to the politically onerous, whether communinists or Nazis, pornographers or religious fanatics.

Raised a genteel Bostonian, Mr. Baldwin converted to a life of social commitment after hearing a 1903 speech by anarchist Emma Goldman. Later, his defense of radical pacifists and "Wobblies" during World War I led to a jail term for preaching draft resistance and, after the war, to his life's vocation of civil liberties.

Not only was Mr. Baldwin present at the creation of the modern libertarian tradition; he must be held responsible for many of its successes. When the ACLU obtained its organizational dossier from the FBI during the 1970s, Mr. Baldwin enjoyed quoting a March 1920 report from bureau operative "836" to a then-young assistant at its Washington headquarters named Hoover. Agent "836" reported accurately that, among other things, the fledgling ACLU supported "free speech, free press, etc." for all groups. To expand the boundaries of that invaluable "etc.," Roger Baldwin devoted his eminently productive and, happily, long life.