It’s an image familiar to millions of Americans: General George Washington standing in a rowboat on Christmas Day, as he leads his troops across the Delaware River from Pennsylvania to New Jersey, in 1776.

The men were headed to Trenton to make a surprise attack on Hessian (German) forces fighting for the British during the American Revolution.

There’s just one problem: The iconic 1851 painting by Emanuel Leutze, Washington Crossing the Delaware (left), captured the drama of the event but didn’t get all of the facts right. Now Mort Künstler, a New York artist who studied historical accounts, journals, and even weather reports, is trying to set the record straight.

In Künstler’s version, above, the crossing takes place on Christmas night in a driving snowstorm. The flag is gone, since the one in Leutze’s painting wasn’t adopted until 1777. Also, Washington and his men aren’t in a small rowboat, but on a flatboat ferry big enough to transport horses and cannons.

“No one in his right mind would have stood up in a rowboat in that weather,” Künstler says. “It would have capsized.”