The line between blatant self-promotion and selfless magnanimity is often hazy, and it takes a delicate sense of balance — or a great gimmick — to neatly straddle the two. Case in point: a young actress, in a rush of wartime patriotic fervor, decides to raise troop morale by a surefire, if unorthodox, method. And if her well-meaning stunt earns her some welcome publicity — well, where’s the harm? Here’s how LIFE magazine described just such a scenario in an article titled “LIFE Goes to an Army Party,” published in the uncertain days of March 1942: At an Army encampment near a southern California aircraft factory last month, perky movie starlet Marilyn Hare embarked on one of the most formidable morale-building projects yet contrived for the U.S. Army. A good fighting machine, she knew, thrives on joie de vivre. From her father, the late Ernie Hare of the famed pioneering radio team call the Happiness Boys, 18-year-old Marilyn had learned the art of evoking merriment in others. But in this hour of national crisis, Miss Hare had evolved a unique inspiration program of her won. It was her aspiration to kiss 10,000 soldiers. Bright and early Feb. 5 squads of soldiers assembled in the balmy California sunshine. Bright and early merry Marilyn arrived for her great undertaking. She mounted a soapbox and as a kind of musical hors d’oeuvre sang “Kiss the Boys Goodbye” to an accordion accompaniment. Then, stepping down, she went to work. First she passed down the aisle giving each grinning trooper a taste of her pretty lips. Since other soldiers had duties elsewhere in camp, she wandered from barracks to soup kitchens to sentry posts. There was no shortage of Marilyn’s war commodity, nor were there priorities or second rations. She left each soldier well-bussed and bemused. At day’s end her kissometer recorded 733 smacks. The effect on morale was terrific. As they staggered back to their chores, Marilyn’s be-lipsticked beneficiaries mumbled dreamily: “We won’t wash our faces for a month.” Alas, there’s no record of whether or not Marilyn, who died in 1981, went on to kiss another 9,267 soldiers to reach her lofty, publicly stated goal. For her own part, she did enjoy a brief, modest success in the movies and, many years later, had small parts on hit TV shows like The Wild Wild West and My Three Sons. Not the enduring fame that, as a young actress, she energetically pursued — but for several hundred grateful American soldiers, she was a star of the first magnitude. Liz Ronk, who edited this gallery, is the Photo Editor for LIFE.com. Follow her on Twitter @lizabethronk.