Hugh Mercer Hugh Mercer ( January 17 , 1726 – January 12 , 1777 ) was a soldier and physician . He initially served with British forces during the Seven Years War but later became a brigadier general in the Continental Army and a close friend to George Washington . Mercer died as a result of his wounds received at the Battle of Princeton and became a fallen hero and rallying symbol of the American Revolution . Early life and career . Mercer was born near Rosehearty , at the manse of Pitsligo Kirk , Aberdeenshire , Scotland , to Presbyterian Minister , Reverend William Mercer of Pitsligo Parish Church and Ann Monro . At 15 , he attended the University of Aberdeen , Marischal College , studying medicine and graduated a Doctor . He was assistant in the army of Bonnie Prince Charlie in 1745 , and was present at the Battle of Culloden when Charles ' Army was crushed on April 16 , 1746 , and any survivors were hunted down and killed . As a fugitive in his own homeland in 1747 , Mercer fled Scotland after months in hiding . He bought his way onto a ship and moved to America , settling near what is now Mercersburg , Pennsylvania , and practiced medicine for eight years . Seven Years War . In 1755 , when General Edward Braddock ' s army was cut down by the French and Indians during the first British attempt to take Fort Duquesne , Mercer was shocked by the same butchery he remembered at Culloden . He came to the aid of the wounded and eventually took up arms in support of the army that a few years back was hunting him , this time as a soldier , not a surgeon . By 1756 he was commissioned a captain in a Pennsylvania regiment , and accompanied Lt . Col . John Armstrong ' s expedition on the raid of the Indian village of Kittanning in September 1756 . During the attack , Mercer was badly wounded and separated from his unit . He trekked 100 miles through the woods for fourteen days , injured and with no supplies , until he found his way back to Fort Shirley , where he was recognized and promoted . He rose to the rank of colonel and commanded garrisons . It was during this period that Mercer developed a lifelong and warm friendship with another colonel , George Washington . Both Washington and Mercer served under British General John Forbes during the second attempt to capture Fort Duquesne . Forbes occupied the burned fort on November 25 , 1758 . Forbers immediately ordered the construction of a new fortification to be named Fort Pitt , after British Secretary of State William Pitt the Elder . He also named the settlement between the rivers " Pittsborough , " which is the location of modern Pittsburgh , Pennsylvania . Forbes ’ s health , which had been poor for much of the campaign , began a rapid decline during his occupation of Fort Pitt . On December 3 , 1758 , now gravely ill , Forbes began the arduous journey back to Philadelphia leaving Colonel Hugh Mercer in command of Fort Pitt . General Forbes died in Philadelphia on March 11 , 1759 . He was buried in Christ Church in Philadelphia . Mercer ' s first task was to construct a temporary Fort to hold the Forks of the Ohio in case the French were able to execute their plans to return in the Spring of 1759 . Drawing of the time call this temporary fortification " Mercer ' s Fort " . Mercer ' s Fort stood at the site of what is today a parking lot between Point State Park and the Pittsburgh Post Gazette Building . After befriending several Virginia men , Mercer moved to Fredericksburg , Virginia in 1760 to begin his medical practice anew at the conclusion of the war . When Mercer arrived in Fredericksburg , it was a thriving Scottish community that must have been a happy sanctuary for a Scotsman who could never again see his homeland . He became a noted member and businessman in town , buying land and involving himself in local trade . He became a member of the Fredericksburg Masonic Lodge in 1767 , and sat as its Master a few years later . ( Two members of this same lodge , Washington and James Monroe , would later become American Presidents , and at least eight members were generals of the American Revolution ( Washington , Mercer , George Weedon , William Woodford , Fielding Lewis , Thomas Posey , Gustavus Wallace , and the Marquis de Lafayette ( honorary in 1824 ) – far more than any other group , institution or organization save the pre - Revolution British Army . This lodge is still in existence today . ) Soon after this , Mercer opened a physician ’ s apothecary and practice . His apothecary in Fredericksburg , Virginia is now a museum . George Washington ' s mother , Mary Washington , became one of Mercer ' s patients , and Mercer prospered as a respected doctor in the area . Mercer married Isabella Gordon and fathered five children : Ann Mercer Patton , John Mercer , William Mercer , George Weedon Mercer , and Hugh Tennant Mercer . In 1774 , George Washington sold Ferry Farm , his childhood home , to Mercer , who wanted to make this prized land into a town where he and his family would settle for the remainder of his days . During 1775 , Mercer was a member of the Fredericksburg Committee of Safety , and on April 25 he was one of the members of the Independent Company of the Town of Fredericksburg who sent a letter of concern to then - Colonel George Washington when the British removed gunpowder from the magazine at Williamsburg . In an August vote , Mercer was excluded from the elected leadership of the new regiments formed by the Virginia Convention because he was a " northern Briton , " but on September 12 he was elected Colonel of the Minute Men of Spotsylvania , King George , Stafford , and Caroline Counties . On November 17 Mercer was one of 21 members chosen for the Committee of Safety of Spotsylvania County . On January 11 , 1776 , Mercer was appointed Colonel to what soon became the 3rd Virginia Regiment of the Virginia Line , and the next day George Weedon was appointed Lieutenant Colonel . Future president James Monroe and future Chief Justice of the United States John Marshall also served as officers under his command . In June 1776 Mercer received a letter from the Continental Congress , signed by John Hancock , appointing him Brigadier - General in the Armies of the United Colonies and requesting him to report to headquarters in New York immediately . Mercer soon left Fredericksburg to join the Continental Army . The American Revolution . Before the New York City Campaign , Washington ordered two forts built to repel the Royal Navy . On the New York side of the Hudson River , Fort Washington was constructed , and Mercer himself oversaw the building of the earthen fortification on the New Jersey side , named Fort Lee . Though bravely defended , the British captured Fort Washington on November 16 , 1776 , and the Americans abandoned Fort Lee four days later . The retreat to New Jersey became known as “ the Crisis of the Revolution " , because the enlistments of most of Washington ' s beaten and down - trodden soldiers ended on New Year ' s Day 1777 . There are rumors that Mercer exclusively originated Washington ' s daring plan to cross the Delaware River and surprise the Hessian s at the Battle of Trenton on December 26 , 1776 , and he was certainly a major contributor to its execution . Because of the win at Trenton ( and a small monetary bonus ) , Washington ' s men agreed to a ten - day extension to their enlistment . When Washington decided to face off with Cornwallis during the Second Battle of Trenton on January 2 , 1777 , Mercer was given a major role in the defense of the city . The next day , January 3 , Washington ' s army was en route to Princeton , New Jersey . While leading a vanguard of 350 soldiers , Mercer ' s brigade encountered two British regiments and a mounted unit . A fight broke out at an orchard grove and Mercer ’ s horse was shot from under him . Getting to his feet , he was quickly surrounded by British troops who mistook him for George Washington and ordered him to surrender . Outnumbered , he drew his saber and began an unequal contest . He was finally beaten to the ground , then bayoneted repeatedly - seven times - and left for dead . When he learned of the British attack and saw some of Mercer ' s men in retreat , Washington himself entered the fray . Washington rallied Mercer ' s men and pushed back the British regiments , but Mercer had been left on the field to die with multiple bayonet wounds to his body and blows to his head . ( Legend has it that a beaten Mercer , with a bayonet still impaled in him , did not want to leave his men and the battle and was given a place to rest on a white oak tree ' s trunk , while those who remained with him stood their ground . The tree became known as “ the Mercer Oak ” and is the key element of the seal of Mercer County , New Jersey . ) When he was discovered , Mercer was carried to the field hospital in the Thomas Clarke House ( now a museum ) at the eastern end of the battlefield . In spite of medical efforts by Benjamin Rush , Mercer was mortally wounded and died nine agonizing days later on January 12 , 1777 . Because of Mercer ’ s courage and sacrifice , Washington was able to proceed into Princeton and defeat the British forces there . He then moved and quartered his forces to Morristown in victory . Because of those victories , Washington ' s army reenlisted , the French finally approved arms and supplies to the Americans and a stunned Cornwallis pulled his forces back to New York to reassess the surprising American successes . The " crisis " had ended , America had the means to fight , and British public support for the war slowly began to wane . A portrait by Charles Willson Peale entitled " Washington at the Battle of Princeton , January 3 , 1777 " displays Washington in the foreground with Hugh Mercer lying mortally wounded in the background , supported by Dr . Benjamin Rush and Major George Lewis holding the American flag . This portrait is the prize possession of Princeton University . Ironically James Peale painted a version of " Battle of Princeton " which shows in the background a very indistinct portrait of Mercer being helped from the ground . Reportedly the Trumbull sketch of Mercer { above } was based on a son of General Mercer . Family lineage and heritage . Succeeding generations of Mercer ' s family have distinguished themselves . Famous direct descendants of Hugh Mercer were Confederate Lt . Col Waller T . Patton and his brothers Col . George Smith Patton and John Mercer Patton , who in turn were ancestors of General George S . Patton , Jr . Other direct descendants include Confederate General Hugh Weedon Mercer ( CSA ) and songwriter Johnny Mercer . In film . In the 2000 television film " The Crossing " , a dramatization of Washington ' s crossing of the Delaware and the battle of Trenton , Mercer is played by Roger Rees .