Answer: The Marquis de Lafayette.
Born into one of the wealthiest families in France, the Marquis de Lafayette landed in South Carolina in 1777 at age 19 to fight for American independence from the British crown. Lafayette presented himself to the Continental Congress in Philadelphia during the summer of 1777 expecting to be graciously accepted into the American military, given his wealth and nobility in France. However, many congressmen were skeptical of the young Frenchman due to their past experiences with most foreign generals who had only joined the war for personal glory. With an earnest belief in the ideals of the American Revolution, Lafayette offered his services as an unpaid volunteer and was soon granted a position as a major general. Lafayette quickly fell into the company of George Washington as his aide-de-camp and the two men formed a bond of philosophy that would last a lifetime.
In September 1777, Lafayette was wounded at the Battle of the Brandywine in Pennsylvania (pictured left) and spent the following winter at Valley Forge. Along with the Continental army, Lafayette fought at the Battle of Monmouth, New Jersey in June 1778. During a return visit to France in 1779, Lafayette secured formal French support for the American cause. The arrival of French forces at the 1781 Battle of Yorktown ensured the American Revolution was all but won with the surrender of British General Charles Cornwallis.
Soon after the battle at Yorktown, Lafayette returned to France and worked in support of a constitutional monarchy in the years prior to the French Revolution. In 1824, President James Monroe invited Lafayette to tour the United States for one year. He accepted and traveled with his son, George Washington Lafayette, to every state. In Philadelphia, festivities honoring Lafayette were held from September 28 through October 5, 1824.