Feb 2, 2023 · Groundhog Day has its roots in ancient midwinter ceremonies. How did the U.S. end up celebrating Groundhog Day in the first place? It dates back to ancient traditions — first pagan, then Christian — marking the halfway point between the winter solstice and spring equinox, says Troy Harman, a history professor at Penn State University who also works as a ranger at Gettysburg National ...