Driving on Mercer Road toward Princeton, the tree line breaks to a grassy open field marked by a lone, resolute oak tree, a stone colonnade, and a wooden house. This quiet expanse - the Princeton Battlefield State Park - and its humble landmarks memorialize a seminal moment in American history:

On this land 240 years ago, George Washington and his volunteer soldiers made the first great strides in securing America's vision for independence.

July Fourth strikes a patriotic chord in every American. On that day in 1776, 13 American colonies joined together with a Declaration of Independence from the British crown, and our journey as a nation began. Six months later, however, independence was a fading dream, crushed by the British army in the opening battles of the Revolutionary War.

But on Jan. 3, 1777, Gen. George Washington and his ragged Continental Army confronted trained British Regulars on frozen farmland in the Battle of Princeton.

Facing yet another defeat, Washington, hat in hand, rode forward to within 30 yards of the Redcoats and waved his arm toward the enemy, yelling, "Halt!" and then "Fire!" As historian Richard Ketchum wrote, "Almost immediately, there were two thundering volleys from the opposing armies and one of Washington's new staff officers, John Fitzgerald, seeing the general out there directly in the line of fire between the two battle lines, pulled his hat over his eyes so that he would not see Washington fall. After the crashing explosion, the smoke gradually cleared, and Fitzgerald looked again, to see the commander in chief still in his saddle, calm and unharmed, waving the troops forward."

The British broke and ran toward Princeton, and for the first time, the Continental soldiers saw the backs of British Regulars as they fled a field of battle. The Battle of Princeton showcased Washington's courage and leadership. He personally led his men in a miraculous charge that secured a decisive victory. On these unassuming yet incredibly historic acres, the fight for American independence, which had seemed all but lost by even Washington himself, was reinvigorated and put the army on a path to ultimate victory nearly five years later at Yorktown.

Today, the Princeton community and the nation are working to achieve another success on the very same battlefield. In December, the Civil War Trust - through its Campaign 1776 initiative to preserve Revolutionary War and War of 1812 battlefields - signed an agreement with Princeton's Institute for Advanced Study to preserve 15 acres where Washington's storied charge occurred. The Trust is now working to raise the needed $4 million to see to it that these acres are saved forever.

The Princeton battlefield is a true national treasure. Established as a 40-acre state park in 1946 that covered only part of the field of conflict, the Princeton Battlefield State Park gradually grew to its present size of 681 acres, even as the crucial site of Washington's charge remained unprotected. The National Park Service has recognized Princeton as one of America's most significant battlefields - as well as a National Historic Landmark.

This place matters.

It is a living monument to our nation's founding. It enshrines and memorializes the sacrifice of the soldiers who drew their last breaths on its frozen ground. It matters to our youth, who can use battlefields as outdoor classrooms. And it matters to the world - a timeless and universal beacon for those who persist in the face of insurmountable odds and almost certain defeat.

We continue to raise the funds to pay for the land at Princeton, and we seek new supporters and partners to the cause. The preservation of these 15 acres of Washington's charge is crucially important not only to memorialize the sacrifices made there, but to allow history buffs and park visitors to continue to see this significant part of the battlefield as Washington and his soldiers saw it - open and undeveloped.

From our smallest towns to our biggest cities, as we gather once again to celebrate the 241st anniversary of our country's independence, we also celebrate this country's unique history. Let us remember that preserving and understanding our history is a light to our future as a democratic nation.

James McPherson, the acclaimed author and historian, is the George Henry Davis 1886 Professor of American History, Emeritus at Princeton University. jmcphers@princeton.edu

James Lighthizer is president of the Civil War Trust. To learn more, visit www.civilwar.org. president@civilwar.org