The Siege of Yorktown, Battle of Yorktown, or Surrender of Yorktown, the latter taking place on October 19, 1781, is a decisive victory by a combined assault of American forces led by General George Washington and French forces led by the Comte de Rochambeau over a British Army commanded by Lieutenant General Lord Cornwallis.

The culmination of the Yorktown campaign, it proves to be the last major land battle of the American Revolutionary War in North America, as the surrender of Cornwallis' army prompts the British government eventually to negotiate an end to the conflict.In 1780, 5,500 French soldiers land in Rhode Island to assist their American allies in operations against British-controlled New York City.

Following the arrival of dispatches from France that include the possibility of support from the French West Indies fleet of the Comte de Grasse, Washington and Rochambeau decide to ask de Grasse for assistance either in besieging New York, or in military operations against a British army operating in Virginia.

On the advice of Rochambeau, de Grasse informs them of his intent to sail to the Chesapeake Bay, where Cornwallis has taken command of the army.

Cornwallis, at first given confusing orders by his superior officer, Henry Clinton, is eventually ordered to make a defensible deep-water port, which he begins to do at Yorktown, Virginia.

Cornwallis's movements in Virginia are shadowed by a Continental Army force led by the Marquis de Lafayette.The French and American armies unite north of New York City during the summer of 1781.

When word of de Grasse's decision arrives, the combined armies begin moving south toward Virginia, engaging in tactics of deception to lead the British to believe a siege of New York is planned.

De Grasse sails from the West Indies and arrives at the Chesapeake Bay at the end of August, bringing additional troops and providing a naval blockade of Yorktown.

He is transporting 500,000 silver pesos collected from the citizens of Havana, Cuba, to fund supplies for the siege and payroll for the Continental Army.

While in Santo Domingo, de Grasse meets with Francisco Saavedra de Sangronis, an agent of Carlos III of Spain.

De Grasse had planned to leave several of his warships in Santo Domingo.

Saavedra had promised the assistance of the Spanish navy to protect the French merchant fleet, enabling de Grasse to sail north with all of his warships.

In the beginning of September, he defeats a British fleet led by Sir Thomas Graves that comes to relieve Cornwallis at the Battle of the Chesapeake.

As a result of this victory, de Grasse blocks any escape by sea for Cornwallis.

By late September, Washington and Rochambeau arrive, and the army and naval forces completely surround Cornwallis.After initial preparations, the Americans and French build their first parallel and begin the bombardment.

With the British defense weakened, Washington on October 14, 1781 sends two columns to attack the last major remaining British outer defenses.

A French column takes redoubt #9 and an American column redoubt #10.

With the American artillery closer and more intense than ever, the British situation begins to deteriorate rapidly and Cornwallis asks for capitulation terms on the 17th.

After two days of negotiation, the surrender ceremony takes place on the 19th, with Cornwallis being absent since he claims to be ill. With the capture of over 7,000 British soldiers, negotiations between the United States and Great Britain begin, resulting in the Treaty of Paris in 1783.