His steamer trunk was packed, his white sailing slacks pressed. He was going off to fight the Great War, and as the train rattled east toward Pelham Bay in New York City, where he would begin classes at the Navy's Officer Material School, my grandfather traveled in torment. "All those long, dark hours across that green landscape," he lamented in a letter written later that evening (June 12, 1917) to Elizabeth Holliday, a St. Louis debutante, "and I composed mentally a thousand letters to you, the wordings of which now desert me, utterly. For what I am going to say probably is inexcusable. Betty, you are the first girl that I've ever cared for. Do you know how it feels to be idealized?"

If she didn't then, she surely would two years later. From 1917 to 1919 my grandfather, working aboard cargo ships that churned through ice on the Great Lakes and dodged torpedoes on the Atlantic, wrote Betty Holliday more than 40 letters. And these were not quick how-de-dos or insipid dispatches of gossip. No, John Jerome Finlay, who was 23 in 1917, was an aspiring novelist who regarded himself, a la F. Scott Fitzgerald, in grandiose terms. He owned a velvet-collared naval cape, for which he shelled out a small slice of his family's oil fortune, and an etched naval sword, and he wrote every one of his missives on fine linen letterhead, in a firm hand that favored curlicue pen strokes over cross-outs, proclamation over hesitancy. "These letters," he declared on May 27, 1918, "have been written in snow-covered tents and in the Biltmore and up in a smelly forecastle. They are milestones along the road of a young man's spiritual growth. Don't ever lose them, Betty. Some day when this war is over, some glorious autumn day, I'm coming back to St. Louis and you will get them out and you and I will drive out to some high hill and laugh and talk and dream."

That glorious day, alas, never came. Betty broke off the courtship late in 1918 -- amicably, it seems. She let my grandfather keep all the correspondence, both his long letters and her chipper notes, and he brought all of these missives with him in a whiskey crate to Evanston, Ill., where he lived with my grandmother after their marriage in 1928. He kept them after that union ended in a bitter divorce a decade later, and he did not throw them out when, as a bald, stoop-backed old man -- a retired writer of advertisements -- he spent his last years judiciously sifting through his personal papers, honing them down to a concise library that would deliver to posterity John Jerome Finlay's life story as he, himself, wanted it told.

My mother, who is a writer of history books, had no choice but to preserve her father's letters in our Connecticut basement. And so last Christmas, 27 years after my grandfather's death, the whiskey crate was still there. I brought it home with me on the plane, and now it sits in my closet.

Andrew Carroll considers me lucky. Carroll, 30, is the curator of a small exhibit that runs through April at the National Postal Museum. "Missing You: Last Letters From World War II" showcases the spare and wrenching works of soldiers who wrote just before dying. In a 1944 letter an Army private tells his mother, "I still count on your tucking me into bed when I get home." A 1945 postcard written from a Japanese POW ship is even more heartbreaking: "Dear Mom and Dad, I guess you can tell Patty that fate just didn't want us to be together."

Carroll has gathered more than 15,000 war missives for a forthcoming anthology. Among his collection is an American Revolutionary War soldier's plea for more blankets; an e-mail in which a female lieutenant attaches, for her parents, a digital photo of a Serbian massacre site; and an eyewitness account of a Civil War soldier being executed for desertion.

Carroll chose to focus the Postal Museum exhibit on World War II because, he says, "a thousand World War II veterans are now dying every day in America. There's a great urgency to honor them, and the best way to do that is by reading their letters. Letters bring history to life. You hold a letter, and you are holding the same piece of paper that the soldier held in a foxhole or in the back of a jeep. You learn that war involves individuals, people with parents and siblings and wives back home, and you see -- people that go to this exhibit will see -- that war is the most vicious experience we can endure."

I share Carroll's pacifist sentiments, no doubt, but as I read my grandfather's letters, I am not struck by the horror of war. I am instead enchanted by a kindred spirit, a writer who reaches me across a chasm of time.

I never really knew my grandfather. He died when I was just 6, and I remember him mainly as cantankerous and apt to bellow threats at my sister and me if we got too crazy while playing on the electric-powered hospital bed he slept in at his retirement home. There was little about him that suggested the early romantic, and it certainly wasn't he who led me to savor good writing. My mother did that. She typed in the kitchen, grinning whenever she turned a good phrase on her manual Royal, and often she recited snippets of poetry. Once, when I came home from school with dirt on my face, she read e.e. cummings's great lines about spring: "when the world is mud-luscious." My mother also organized my sock drawer and sponged the crumbs off the kitchen counter, though, so when I was in college and rooting about for some stirring proof that I had prose in my blood, I did not look to her. I looked instead for myth, for some whiff of ancestral greatness. I descended the stairs into the basement.

There were whole files of my grandfather's letters-to-the-editor down there, and crumbling envelopes filled with short stories and rejection slips, and diaries and advertisements, and a thin stack of letters from various luminaries who wrote back to my granddad -- Alfred Hitchcock, Eleanor Roosevelt and Peace Corps chief Sargent Shriver, a personal friend who, in six handwritten pages, confided that he shared my grandfather's zeal for Roman Catholicism.

Such discoveries were heartening, but still my grandfather's writings left me somewhat unhappy. I could taste his divorce in their swagger and bite (did he really have to speak of "nailing the lid" on Nelson Rockefeller's "political coffin"?), and I can hear his lonely fanaticism in their ardor. "The Vatican and the White House!" he wrote Time magazine in 1941."There's a combination that can clear the world's path of evil."

The war letters I found last Christmas are different. Life had not yet encrusted Jack Finlay, and his prose, even at its most cliched, delivers a fine sense of wonder. It reads like lyrics sung from a wide-open heart. "Out on the deck," he wrote from a swaying ship off Virginia on April 9, 1918, "it is perfectly marvelous -- if you don't mind wading against occasional rushes of water about two feet deep. And the nights are wonderful with a great big moon, a phosphorous sea and millions of stars and two or three of us in summer uniforms sipping something cool." The script in this letter is jagged, jarred by the waves, and on the third page there are a few water-splotched words. I inhaled their smell the other day, hoping for some scent of salt, and then I kept reading.

My grandfather met Betty at a country club in St. Louis, in June 1915, when the night sky just happened to be "a halo field bathed in the moon's radiance." A fox trot, "The Murray Walk," wafted through the warm evening, and I imagine it buoying them along, lilting them over a vast floor of parquet. There followed a private moment -- a shared cigarette on the patio, perhaps, his knuckles grazing her fingertips with the transfer of smoke -- and then they whirled away, separately, that evening, toward other delights. My grandfather and Betty may have shared a few dinners and cocktails over the subsequent months but they never lingered needfully with each other or made any vows -- I am sure of that. The letters make clear that Betty Holliday was no waiting Penelope, and that my grandfather saw too much splendor in the female form to be ploddingly loyal. "Who said war is hell?" he once asked Betty, in a booze-inspired scrawl written from shore. "In a moment, we are dining with two of the most wonderful looking girls."

He thought Betty was lovely as well, but he probably never even kissed her. Early in the correspondence, he apologizes for an "unreciprocated kindness," a "rather unexpected action on the balcony" and later he dreamed of "kissing you, lightly." Whether it happened or not matters little, though, for Betty seemed far more romantic than any lover ever could be. She was my grandfather's muse. "You are my only sympathetic listener," he wrote her once. "Dear Jack," she responded, before rushing off to a dinner party, say, or a Junior League ball. "The `line' you sent was a whizz -- the best I've read. I wasn't feeling very high at the time and it raised me up quite a lot."

It was all the encouragement my grandfather needed. In serial form, he delivered Betty his life story. After two years in advertising, he quit his job in 1915 to answer what he sonorously described as "the call to active service." Then, after three months of training, he and 60 other members of the Navy Auxiliary Reserve steamed out of Chicago onto Lake Michigan for their inaugural run. The USS Gopher, on which he served as a navigator, carried iron ore mined in Minnesota's Mesabi Range. The sailors took the raw mineral down Lake Superior, toward Cleveland, to be shaped into guns, tanks and ships. It was pedestrian toil. Lying in his bunk on cold Midwestern nights, my grandfather longed to become one with the war's greater theatrics. "I haven't been under fire yet," he wrote in October 1917, "but I hope to Heaven I will be. I'm in this war to see action -- the more, the merrier." A few days later they went back to Duluth for more ore.

Luckily, he had the gift of finding drama in everyday life. "Picture me shaving in the misty dawn," he wrote Betty once, "a steel mirror hung on a fence post, a blade of grass stuck in the soap." When he had to stand watch on the ship's bridge in the fog, he recounted his labors thusly: "Hours without end we stood, three of us always, trying to pierce the blank curtain that rolled ahead of us." And when at last he hit the ocean and glimpsed some real danger, in the form of 125 mph winds off Cape Hatteras, his voice rose in a Conradian crescendo. "With each fresh impact against the waves," he wrote, "the ship vibrates from stem to stern, her rotten timbers creak, snap, groan. With every rush of water, little rivulets descend from the deck to mingle on the ward room floor with dirt, linoleum, newspaper. A single oil lamp swings drunkenly in its gimbals."

Betty's response: "I can hardly picture that wonderful, well-groomed officer in the photo you sent being tossed to and fro like a piece of driftwood and covered with grease and oil and a lot of other horrible things!"

Her letters reached him on the muddy streets of shipyards, in dingy mess halls and at the front desks of nowhere hotels. He read one letter standing in line at a canteen feeling "so cold and shivery I could hardly keep the paper still." He reread another four times. He begged her to write longer, to be more descriptive, and he celebrated their fleeting wartime encounters as almost holy. "There was a glimpse of Eden," he wrote after one evening of merriment in St. Louis, "and then a sudden withdrawal."

To Europe. My grandfather embarked on his first -- and only -- journey across the Atlantic in May 1918. Then he spent the summer in France where, mysteriously, he and his mates were exiled from mail reception. Her letters stopped coming. His output meanwhile dwindled as drama -- real drama! -- consumed him. He caught influenza in the epidemic of 1918, losing 15 pounds in nine days. His ship narrowly missed slamming an iceberg and was fired at by two German submarines so close that the related telegraphs, which my grandfather saved in a leather-bound scrapbook, read only "SOS! SOS SOS!" By the time he was able to write at length, he sounded weary and vulnerable. "I hope," he said, "to find a number of letters from you when I return and open my bag. This not hearing from a girl for two whole months gives me a very forgotten feeling."

I think my grandfather hoped to find Betty waiting for him at the dock, her arms outstretched, quivering for embrace. Ms. Holliday had her own aspirations, though, and they involved a fellow named Hamilton. My grandfather learned of Betty's commitment to Hamilton from a friend in St. Louis, and the next time he wrote Betty, many months later in February 1919, his prose limped, as though it had been clubbed in the knees. "Betty," he said, "you deserve a man bigger physically, more impressive personally. And I say this, as you know, without any sour grape suspicion."

It was his final letter. Betty Holliday quickly faded from my family history. I have no idea what became of her, and her exit doesn't bother me, really, except for this: My grandfather believed in her, believed in her as a writer of fiction believes in his characters. In Betty Holliday, he invented a woman who could share with him in the rapture of being young and on an adventure. His words would never conjure such magic again. And so the last note he sent before learning of Hamilton, the note he sent Betty from Paris amid the German onslaught of 1918, is for me the saddest and sweetest of all his letters. "Having the time of my life," he wrote. "Tennis, swimming, teas and dinners with charming French girls. The beauty here is punctuated by the boom of long range shells (one just went off in the front of the hotel), but no one seems to mind, unless they are actually hit. Paris is heaven, absolutely! I will try to write from the ship. As always, Jack."

Bill Donahue is a freelance writer living in Portland, Ore. Interested readers are welcome to send copies of wartime correspondence to Andrew Carroll at: Legacy Project, P.O. Box 53250, Washington, D.C. 20009.