P HILADELPHIA — Hers has always been one of the more astonishing, if little-known, tales of the American Revolution: a woman who stitched herself a uniform, posed as a man and served at least 17 months in an elite unit of the Continental Army. Wounded at least twice, Deborah Sampson carried a musket ball inside her till the day she died in 1827.

While historians agree that Sampson served in uniform and spilled blood for her country, gaps in the account have long led some to wonder whether her tale had been romanticized and embellished — possibly even by her.

Did she fight in the decisive Battle of Yorktown, as she later insisted on multiple occasions? And how did she keep her secret for the many months she served in Washington’s light infantry?

Now, scholars say the discovery of a long-forgotten diary, recorded more than 200 years ago by a Massachusetts neighbor of Sampson, is addressing some of the questions and sharpening our understanding of one of the few women to take on a combat role during the Revolution.