He had all the presence of "a withered little apple-john," someone once wrote after shaking his hand. Plagued by hemorrhoids and fainting spells, which kept him out of the army, and mumbling, which dulled his oratory, he hardly seemed a hero.

He may have been a Founding Father, but James Madison never won hearts like his friend Thomas Jefferson, nor even like his wife Dolley. "The trouble is," complains Robert A. Rutland, editor of Madison's voluminous papers, "we're so accustomed to show people, that when we get an honest-to-God intellect, we don't know what to do with them. We want a few spangles and they don't have spangles."

The nation that owes Madison so much waited nearly 150 years to honor him with a memorial: a mammoth marble monolith housing a Library of Congress annex. But the building's so bland and scary on the outside, the exhibition on the inside, "James Madison and the Search for Nationhood," isn't getting the attention it deserves.

Time's growing short. Though the show, which opened last November, runs through August, some of its better pieces, like Madison's beloved easy chair (from the James Madison Museum) and an 1804 Gilbert Stuart portrait (from the Colonial Williamsburg Foundation), will be gone by the end of May. "We just can't keep these things indefinitely," says curator Ingrid Maar.

Beyond a cumbrous hall with quote-covered panels and a statue of Madison, seated, looking vaguely benumbed, the gallery overflows with the man and his times. There are letters and notes in Madison's tiny, precise hand, busts of him and the former Dolley Payne Todd, paintings of him and his contemporaries -- a huge oil of Jefferson, from the West Point Museum, lords it over the second floor -- political cartoons, bric-a-brac, furnishings, household ledgers, maps and floorplans, a family Bible: rich confirmation that Madison lived and breathed.

He was born in 1751, the eldest son of plantation owner in Orange County, Virginia. Sickly, he nevertheless came early to rigorous education. By 12, as Rutland writes in the book published for the show, "the lad knew Latin tolerably well and had the foundations for his later skills in French, Greek, Italian, Spanish, and Hebrew."

He left Montpelier, the family estate, for the College of New Jersey at Princeton -- "an indiscreet experiment of the minimum of sleep & the maximum of application," as he reported in one of his letters -- and graduated on October 7, 1771, as proclaimed by the parchment-and-silk diploma displayed under glass.

The rest of the show, with items arranged chronologically, covers Madison's career as young legislator and logician, architect of the Constitution, prolific essayist, adviser to George Washington, adversary of Patrick Henry, secretary of state under Jefferson, the nation's fourth president -- with the dubious distinction of fleeing the White House, which the British then burned -- and finally elder statesman. Withered like a dried apple, yet sharp as a saber, he lived to be 85. Among his last pursuits was a scheme to end slavery, which he had long considered a necessary evil, though lately more evil, by returning blacks to Africa under the auspices of his American Colonization Society.

When he was 79, Madison sat for painter Asher B. Durand, who produced a portrait, lent to the show by The Century Association, of a wizened old chap with white wisps of hair, the gaunt face stern and pedantic. Madison may have had a sense of humor, but the show offers no evidence of it.

Here and there, from the welter of Madison's public life, spring some clues to the private man. He had, a young friend wrote, a "small and delicate form. . .his form, features, and manner were not commanding, but his conversation exceedingly so." Of Dolley Madison, who, at 5 feet 7 towered over her husband, another acquaintance wrote, "I never saw a lady who enjoyed society more than 9she0 does. The more she has round her, the happier she appears to be."

Of the letters on display, many from the Library of Congress's collection, perhaps most touching is the final exchange in 1826 between Madison and Jefferson, best of friends for nearly half a century.

From his deathbed at Monticello, Jefferson wrote: "If ever the earth has beheld a system of administration conducted with a single and steadfast eye, to the general interest and happiness of those committed to it, one which, protected by truth, can never know reproach, it is that to which our lives have been devoted. To myself you have been a pillar of support thro' life, take care of me when dead, and be assured I shall leave with you my last affections."

Madison, from Montpelier, replied: "You cannot look back to the long period of our private friendship & political harmony with more affecting recollections that I do. . . Wishing & hoping that you may yet live to increase the debt which our Country owes you, and to witness the increasing gratitude, which alone can pay it. I offer you the fullest return of affectionate assurances."

Accustomed to having the last word, Jefferson probably never lived to read it.

JAMES MADISON -- At the James Madison Memorial Building of the Library of Congress, First Street & Independence Avenue SE.