While holding off the impending army, Davis organized a sly, orderly escape for him and his men over an elevated railroad bridge that swung a treacherous 40 feet over the Monocacy River.
The maneuvers - during the July 9, 1864, Battle of Monocacy - won the then-24-year-old Davis a promotion to captain and the Medal of Honor.
His descendants, once oblivious that they were heirs to such an amazing feat, kept his Civil War belongings in a shoe box until recently.
"As my family dwindled down and my aunts passed on, the things came to me," June Davis Kenney said Thursday at a small ceremony at Monocacy National Battlefield, when she officially handed George Davis' belongs over to museum curator Gloria Baker.
She said the box of old heirlooms came to life when her husband, Donald Kenney, did a family genealogy and discovered her great-grandfather's extraordinary role in the Civil War.
This week, the Kenneys and their grandson - George Davis' great-great-great-grandson - drove a camper down from Vermont to make the first-ever donation of its kind to the Monocacy Battlefield museum.
They're also touring the battlefields that now give new texture to their family heritage.
"When I first found out ... I was, like, OK, whatever. Then it started sinking in. My great-great-great-grandfather was in the Civil War and won a Medal of Honor. Now it means everything because I've seen where he walked. Wow," said 11-year-old Jacob Robert Kenney.
"I'm glad his things are in a museum. What if our house burned down? They're now more protected," he added.
Only two Medals of Honor - the nation's highest military honor - were given during the Battle of Monocacy, and 1,200 total throughout the four-year Civil War
The medals are given by Congress for life-threatening bravery above the call of duty.
Davis' medal is not part of the collection. Kenney said her father had it with other heirlooms in a trunk in Massachusetts when their home was burglarized in the 1950s.
The medal and Davis' sword were stolen. Kenney said her father could have petitioned Congress for a new one, but he has since passed away.