"Cold.

It is so damnably cold."

It is Christmas Day in Northern Pennsylvania. A freezing, exhausted group of men, led by General George Washington, march through an icy, driving rain and snow.

Barely half of them are healthy enough for duty. Hundreds will collapse from sickness and exhaustion as they march through the night.

One third of them don't have boots. Their rag-wrapped feet literally leave a trail of blood in the Pennsylvania snow.

But on their shoulders literally rests the fate of the Revolution and the Republic.

Their password -- "victory or death" -- is not symbolism. It is their reality.

And they have a message for those of us living today: The next time someone tells you we can't turn America around; The next time someone tells you we can't overcome the challenges we face unless we create a "new" America and a new kind of American -- Tell them to read the story of George Washington and his men.

"These Are the Times That Try Men's Souls"

On Monday, October 19 at Mount Vernon's fantastic new Education Center, historian William Forstchen and I launched our new novel, "To Try Men's Souls: A Novel of George Washington and the Fight for American Freedom." (You can watch video from the event at the book's Web site, www.totrymenssouls.com.)

"To Try Men's Souls" is the wrenching, first person account of General George Washington's 1776 sneak attack on Trenton after crossing the Delaware River. This tale of heroism and sacrifice is told through the eyes and private thoughts of General Washington, writer Thomas Paine, and Jonathan Van Dorn, a young private in the struggling colonial army.

It takes its title from Thomas Paine's famous work, "The Crisis," which opens with a phrase that captures perfectly the heroism and endurance displayed by Washington and his men: "These are the times that try men's souls..."

Pull Your Foot Up Out of the Slop, Stagger Forward Another Step

"To Try Men's Souls" is a story of the miracles that can be achieved by a free people with courage and a willingness to endure.

It is also a riveting story of men versus the elements.

As Washington and his men march, a storm bears down on them, turning frozen earth to mud. Through the eyes of a young soldier, "To Try Men's Souls" describes the unimaginable conditions these American heroes faced:

"Raise your foot, put it ahead of you, heavy mud caked thick to each boot. Put your foot forward, sink into the congealing glue nearly to the boot top, sometimes the chilled slop spilling down inside. Pull your other foot up out of the slop, stagger forward another step. There was no longer any semblance of a marching column, just an endless weaving line of men ahead, the last few stragglers of this broken army. Take a step, move forward another two feet, curl your toes inside your boot to hold tight to it so it isn't sucked off. Take another step."

The Storm that Washington Called "Our Christmas Miracle"

But the storm that creates such hellish conditions for the American rebels is the same storm that General Washington calls "our Christmas miracle."

"To Try Men's Souls" tells how, because of the bad weather, the British-paid German mercenaries that were Washington's target in Trenton stayed in that night. Even though the weather caused the Americans to arrive four hours late -- well after dawn -- when they got to Trenton, the Hessians were asleep in their beds.

Despite being heavily outnumbered, Washington and his men won the battle of Trenton. Their victory reinvigorated the cause of American freedom.

Washington's "Christmas miracle" was the turning point in the Revolutionary War and the birth of America.

Thankfully, none of us can imagine the hardships that these American patriots endured that night in 1776.

Equally thankfully, all of us continue to benefit from their sacrifice.

"To Try Men's Souls" is a work of historical fiction with a powerful message for today: Endurance and sacrifice for the cause of freedom are a part of America's DNA. Those who argue otherwise are misreading our history and mischaracterizing our nation.

To "Try Men's Souls" is available now in either hardback or audio form. Go to www.totrymenssouls.com for links to buy the book, watch video, and listen to a free audiobook sample.

Newt Gingrich is Fox News contributor, author and former Speaker of the House.

Newt Gingrich, a Republican, was speaker of the United States House of Representatives from 1995 to 1999. He is the author of the new novel "Treason" (Center Street, October 11) and co-author, with his wife Callista Gingrich, of "Rediscovering God in America: Reflections on the Role of Faith in Our Nation's History and Future" (Center Street, May 17, 2016).