At a reception in the ornate and elegant old Patent Office, after one of the numerous Franklin D. Roosevelt commemorative events in Washington, a guest remarked somewhat sardonically about the occasion: "What difference does it make, and why should anyone pay attention? Those who were born after he died have no idea who he was and could care less anyway."

Whether she's correct about the public and FDR isn't the point here, though I suspect she's wrong on both counts. The point involves the uses of history, and what lessons, if any, we draw from them.

We've been steeped in history of late in Washington, even more than usual in this capital, where the past is so visibly evoked all around us in monumental marble.

Our museums are filled with special FDR centenary exhibits. Television, in the form of ABC's three-hour documentary on the Roosevelt years, has provided a memorable example of what electronic journalism can accomplish with sounds and scenes from the past along with analysis of how those events affect us now.

The newspapers offer evidence of how much remains unknown about the presidents who led us and the crises with which they dealt. Front-page headlines about FDR secretly recording his Oval Office conversations in 1940 are followed by others about the vastly more extensive John F. Kennedy recordings of critical moments during his term. And, we're told, an even greater reserve of similar tapes awaits public scrutiny in the Lyndon B. Johnson collection in Texas from his presidency. All the while we still know nothing about what remains undisclosed in the great bulk of thousands of hours of Richard M. Nixon's secret tape-recordings.

And, oh, yes, Dwight D. Eisenhower apparently recorded conversations secretly too, extensively over a five-year span of his presidency, according to the Los Angeles Times.

In light of such vital unpublished primary source material, every available account--biography, psychobiography, history, memoir, whatever--about the lives and times of these leaders is, on the face, woefully incomplete.

No sooner has this spate of historical observances and disclosures begun to pass than we approach our annual ritual glance at another towering figure from our presidential past, Abraham Lincoln. And here, too, a fresh look becomes rewarding.

The lanky figure of Old Abe prowls through Richard M. Lee's fascinating new book, "Mr. Lincoln's City" (EPM Publications Inc.). We see our greatest of presidents moving through the streets of wartime Washington, performing an act of charity here, compassion there.

He visits the hospitals scattered across the city where, at various times during the Civil War, as many as 50,000 soldiers lay stricken. We see him pausing to talk, murmur a "God bless you," and move quietly on to the next veteran suffering wounds from battles raging around the capital.

Lee, a retired major general beginning a second career as a historian, retells an incident from a surgeon's memoirs. Dr. John Brinton describes conducting a particularly difficult operation, at Washington's Armory Square Hospital, during which he removed a man's arm at the shoulder. When the operation was completed, his assistant congratulated the surgeon.PAST 6

From behind came the sound of a solemn, troubled voice: "But what about the soldier?"

Startled, Dr. Brinton turned and saw a worried president looking down at them.

As always with Lincoln, these are touching stories, welcome reminders of his humanity, and there's no doubt that they depict the real Lincoln.

While Lincoln naturally adds a majesty to these pages, as Lee's title implies, the Civil War capital is the real hero of his book. It is his portrait of Washington and what it represents to the United States that gives his work special signficance now. With the aid of many maps and photographs, and in a compelling text, Lee shows how the sleepy southern city exploded during wartime to become a true national capital and symbol of a reunited country. Nation-building, driven and directed by the raw energies and new talents flocking to the federal capital, rose out of the ashes of the Civil War. The war dramatically changed Washington and the country, and linked the two as never before.

From a small, backward city of 63,000 people, Washington overnight grew to 200,000 civilians. At times the same number of soldiers were locked in combat in the surrounding countryside. The social complexion of the city and the nature of federal government's relationship to the rest of the nation were altered fundamentally.

I found one passage from that long ago time relevant to the Washington of today:

"As the war moved toward its bloody climax in 1864, and the city overflowed with the horror of far too many sick, wounded and dying men, an epidemic of gaiety, extravagance and party-going infected society. Perhaps it was a reaction to so much tragedy. On their way to one festivity or another the carriages of the rich and pleasure-bound mingled in the streets with seemingly unnoticed lines of muddy ambulances drawn by plodding horses toward the hospitals.

"Excluded from the social life of the . . . elites, a large, hard-working middle class went about its daily business in the city. Among them were the middle and lower levels of the clerks whose ranks, rising from 1,500 in 1861 to over 7,000 in 1865, had to cope with the mushrooming workload of war. They received small salaries, lived in crowded rooming houses and ate their meals at common tables. Even in good times clerks barely made ends meet; their families generally lived away from the expensive capital. With a wartime inflation gripping the country, wages drifted behind prices; in 1864 retail prices rose 76 percent over those in 1861 and the cost of room and board rose by 150 percent. Clerks were hard pressed but the job they did before the day of typewriters and telephones was an essential one. According to a popular saying, 'The flying fingers of thousands of clerks did all the business of government.' "

It's not outright war that now envelops Washington, but a fateful battle, nonetheless.

In historic stakes, the political struggles of the present-day capital, highlighting as they do the values of the affluent, the workings of the permanent government and the relationship of Washington to the country, are certainly the most significant since Franklin Roosevelt's time, and quite likely Mr. Lincoln's.

You don't even need the sensational secret historical tapes to figure that one out.