Question: Who's son concluded a set of treaties which ended the American Revolutionary War?

Context paragraphs:
George Morgan (merchant): George Morgan (1743 – March 10, 1810) was a merchant, land speculator, and United States Indian agent during the American Revolutionary War, when he was given the rank of colonel in the Continental Army.  He negotiated with Lenape and other Native American tribes in western Pennsylvania to gain their support during the American Revolutionary War.  An associate of the Lenape chief White Eyes, Morgan cared for his son George Morgan White Eyes for several years after White Eyes died.

Last surviving United States war veterans: The book "The Last Men of the Revolution" was compiled by Rev. E. B. Hillard and published by N. A. & R. A. Moore in the year 1864, the book claimed to include photos and biographies of six of the last surviving Revolutionary War veterans.  None of the men interviewed in the book would become the last surviving Revolutionary War veteran but the photos published in the book are some of the few surviving photos of American Revolutionary War veterans.

Treaty of Alliance (1778): The Treaty of Alliance with France or Franco-American Treaty was a defensive alliance between France and the United States of America, formed in the midst of the American Revolutionary War, which promised mutual military support in case fighting should break out between French and British forces, as the result signing the previously concluded Treaty of Amity and Commerce.  The alliance was planned to endure indefinitely into the future.  Delegates of King Louis XVI of France and the Second Continental Congress, who represented the United States at this time, signed the two treaties along with a separate and secret clause dealing with future Spanish involvement, at the hôtel de Coislin (4, place de la Concorde) in Paris on February 6, 1778.  The Franco-American alliance that would technically remain in effect until the 1800 Treaty of Mortefontaine, despite being annulled by the United States Congress in 1793 when George Washington gave his Neutrality Proclamation speech saying that America would stay neutral in the French Revolution.

Historic Camden Revolutionary War Site: Historic Camden Revolutionary War Site, is a national historic district and open-air museum located in Camden, Kershaw County, South Carolina.  Roughly 40 minutes away from Columbia, South Carolina the state capitol it is one of the states largest tourist attractions.  The 107-acre site is also known as Historic Camden Revolutionary War Restoration and as the British Revolutionary War Fortifications.  Camden contains preserved structures and grounds that are representative of the Southern theater of the American Revolutionary War.  The site is managed by a consortium of private donors and local governments, the area is also an affiliated unit of the National Park Service.

Peace of Paris (1783): The Peace of Paris of 1783 was the set of treaties which ended the American Revolutionary War.  On 3 September 1783, representatives of King George III of Great Britain signed a treaty in Paris with representatives of the United States of America—commonly known as the Treaty of Paris (1783)—and two treaties at Versailles with representatives of King Louis XVI of France and King Charles III of Spain—commonly known as the Treaties of Versailles (1783).  The previous day, a preliminary treaty had been signed with representatives of the States General of the Dutch Republic, but the final treaty which ended the Fourth Anglo-Dutch War was not signed until 20 May 1784; for convenience, however, it is included in the summaries below.

Robert Plampin: Vice-Admiral Robert Plampin (1762 – 14 February 1834), was a British Royal Navy officer during the late 18th and early 19th centuries, serving in the American Revolutionary War, the French Revolutionary Wars and the Napoleonic Wars, but best known for his time as commander of the British colony of Saint Helena in the South Atlantic during the period when former Emperor Napoleon Bonaparte was imprisoned there.  Born into a Navy family, Plampin went to sea at age 13 and fought throughout the American Revolutionary War, based principally in the Caribbean Sea.  During the French Revolutionary Wars, Plampin served in a number of ships with mixed success, once being involved in a shipwreck and twice serving ashore during sieges.  After the Peace of Amiens, Plampin took command of the ship of the line HMS "Powerful" and operated successfully in the Atlantic and the Indian Ocean.  In 1816, following the defeat and capture of the French Emperor, Plampin was placed in command of the squadron at the Cape of Good Hope, which also had responsibility for Saint Helena, which Plampin regularly visited and had numerous conversations with Napoleon.

Levi Casey (politician): General Levi Casey (c. 1752 – February 3, 1807) was a United States Representative from South Carolina.  He was born in South Carolina and served in the South Carolina militia during the American Revolutionary War.  Son of Abner Casey, he served in the American Revolutionary War along with his step brothers, brother(s) and nephews.  One of his stepbrothers, Benjamin Casey was killed in action at Camp Middlebrook, New Jersey.  He married Elizabeth Duckett in 1775.  He reached the rank of brigadier general in the South Carolina militia.  After the war, he served as justice of Newberry County Court in 1785.

John Petty, 2nd Marquess of Lansdowne: John Henry Petty, 2nd Marquess of Lansdowne (2 May 1765 – 15 November 1809) was a British peer and politician.  He was the eldest son of William Petty, 1st Marquess of Lansdowne, known to history as the Earl of Shelburne, the British prime minister who concluded the Peace of Paris recognising American independence, by his first wife, Lady Sophia Carteret.

The Patriot (2000 film): The Patriot is a 2000 American epic historical fiction war film directed by Roland Emmerich, written by Robert Rodat, and starring Mel Gibson, Chris Cooper, Heath Ledger, and Jason Isaacs.  The film mainly takes place in rural Berkeley County, South Carolina, and depicts the story of an American Colonist, nominally loyal to the British Crown; in both South Carolina and North America; who, is swept into the American Revolutionary War when his family is threatened.  Benjamin Martin is a composite figure the scriptwriter claims is based on four factual figures from the American Revolutionary War: Andrew Pickens, Francis Marion, Daniel Morgan, and Thomas Sumter.

Nathan Hale (colonel): Nathan Hale (September 23, 1743 – September 23, 1780) was an American Revolutionary War Officer.  He was born in Hampstead, New Hampshire, son of Moses and Elizabeth (Wheeler) Hale.  In his teens he moved with his family to Rindge, New Hampshire.  He married Abigail Grout, daughter of Col. John and Joanna (Boynton) Grout of Lunenberg, Mass."At the organization of the town of Rindge in 1768, Nathan was chosen the first constable of the town.  He was moderator of the annual town meetings in 1773, 1774 and 1775.  As early as 1774 he was captain of a company of 'minutemen' and on the alarm of the battle of Lexington, 19 April 1775, he led his company at once to the field.  Four day after he was commissioned major in Col James Reeds regiment, and thenceforward continued in active service until his capture."  Hale participated in the American Revolutionary War and fought in the Battle of Lexington and Concord, Battle of Bunker Hill Siege of Fort Ticonderoga, and Battle of Hubbardton.  Hale was taken prisoner by the British.  He died on September 23, 1780 at the hands of the British at New Utrecht, LI, New York.

Supporting paragraphs: John Petty, 2nd Marquess of Lansdowne Peace of Paris (1783)
Answer: William Petty