At the end of June news reached Clinton of a possible French attack on New York, and he left the south, taking with him 4,000 of his best men and leaving Charles Cornwallis in charge. Cornwallis had served well in a series of subordinate roles, and was eager to take command, but his experience of independent command was not to be pleasant. South Carolina rapidly descended into chaos. A significant number of loyalists did now appear, but so did as many rebels. Moreover, the actions of the loyalists were often indistinguishable from banditry, and forced many ex-rebels back into the field. Cornwallis was forced to establish bases across the state, each one a drain on British resources. One of the British bases, at Camden, attracted the attention of the newly appointed American commander in the south, Horatio Gates. Cornwallis was able to reach Camden before Gates, and on 16 August 1780 inflicted a crushing defeat on the Americans (Battle of Camden).
This was the high point of Cornwallis’s campaign. In September he launched an invasion of North Carolina, which never achieved any momentum and had to be abandoned after the force guarding his left flank was destroyed at the battle of King’s Mountain (7 October 1780). The following year Cornwallis launched another invasion of North Carolina. Once again, his campaign was crippled by the loss of a major detachment, this time at the battle of Cowpens (17 January 1781), where Tarleton’s Legion was badly mauled by Daniel Morgan. After a futile attempt to chase down Morgan, Cornwallis decided to retreat south. The new American commander, Nathanael Greene, followed south with a force that outnumbered Cornwallis. On 15 March 1781 Greene decided he was ready to offer battle, but despite outnumbering the British two to one the battle of Guilford Court House was a British victory. The problem for Cornwallis was that he could not afford the losses he had suffered in victory. It was clear that the expected loyalist risings in North Carolina were not happening. Cornwallis looked for a new strategy, and his mind moved to Virginia and the Chesapeake. Early in 1781 a British army commanded by Benedict Arnold had established itself on the coast of Virginia. Cornwallis proposed a British concentration in Virginia, supported by troops from New York. With a large army at his disposal, Cornwallis could then attempt to win a decisive victory. He had not learnt from his time in the Carolinas that battlefield victories would not lead to a restoration of British control over the colonies. If Camden had not restored British control over South Carolina, then why should a victory in Virginia be any different?
Abandoning his command in the Carolinas, Cornwallis and a weary band of just 1,000 men made their way north to Virginia. They finally reached Petersburg, Virginia, at the end of May. He arrived to find his friend William Phillips had died five days earlier. The 5,000 British troops in Virginian were now under the command of Benedict Arnold, with orders to establish a base on the Chesapeake but not to undertake any major action. Clinton received news of Cornwallis’s move at about the same time he arrived in Virginia. He had no interest in the idea of a major campaign on the Chesapeake, and was obsessed with the possibility of a French led attack on New York. His orders to Cornwallis were for him to establish a naval base on the Chesapeake, capable of sheltering ships of the line. If this base had been established, the British would have had a line of strongholds from New York to Charleston that would have allowed them to strike at will along most of the American coast. Clinton also ordered Cornwallis to prepare to return some of his troops to New York to prepare for a planned expedition into Pennsylvania.
Cornwallis was free to act almost at will in Virginia. The Marquis de Lafayette had command of the small American army present to face him, but only agile manoeuvring on his part kept his army safe. One mistake could have been fatal. On 6 July Anthony Wayne came close to disaster when he was ambushed by Cornwallis at Greenspring and was only extracted with difficulty. The disaster to come was not inevitable. At any point before mid-September Cornwallis could simply have marched away south. After receiving a series of contradictory orders over the summer, Cornwallis finally decided to fortify Yorktown with his entire force, taking advantage of Clinton’s orders to return any troops he could spare. On 2 August, the British forces began to dig in at their new base.
In June news reached Washington of another French fleet heading to American waters. Admiral Grasse had managed to evade the Royal Navy at Brest, and was heading for the West Indies. It was possible that the combined French fleets would be able to gain temporary control of the seas around the United States, but for two months nobody knew where Grasse would sail, or in what strength. On 14 August, the news finally arrived. Admiral Grasse, with twenty nine ships and 3,000 men, was heading for Chesapeake Bay and a collision with Cornwallis.
Washington leapt at the chance to win a major victory. If he could transport the American and French armies from New York and Newport down to Yorktown and persuade Admiral Barras to join Admiral Grasse, then Cornwallis would have little chance of escape. The key was naval control. If the French fleet lost control of the seas then Clinton could rush troops from New York, and it would be the British seeking a decisive battle. Washington decided to take the risk, and was able to gain French support. Now all he had to do was move the combined armies 450 miles from New York to Yorktown.
That freedom did not last much longer. The march south began on 19 August. This was a dangerous moment – if Clinton had realised what was happening, he could have launched an attack on the American armies as they marched. To fool him, Washington feinted towards New York, before turning his armies south. Clinton in New York was uncertain about Washington’s destination until 2 September, when the American armies had already reached Philadelphia. The essence of Washington’s plan was speed. Benjamin Lincoln, in command of the march, managed to get his Continentals 450 miles south in remarkably good condition. On 28 September the allied armies moved into camp two miles from Yorktown. Cornwallis was now trapped.
Cornwallis was badly outnumbered. He had 6,000 regular troops, with another 1,500 drawn from the fleet for a total of around 7,500 men. Facing him were 7,000 American regulars, 4,000 militia, 5,000 French regulars and 3,100 French marines (a total of 19,000 men, of whom 12,000 were professional soldiers). The allies had at least as big an advantage in artillery. His only hope was that Clinton would send a relief force from New York. If that was to happen, then it would have to happen quickly. Yorktown could not hold for long.
Siege warfare at this period was highly formalised. The French and Americans had the strength to follow the rules. A series of parallels would be build – fortifications parallel to the defences, from where a devastating artillery bombardment could be sent against the defenders. The first parallel, 600 yards from the British line, was started on 6 October. By 9 October they were ready to open fire. The bombardment was devastating. At such short range the French artillery was depressingly accurate, with the American artillery not far behind. On the second day of the bombardment, the British were forced to stop firing at day to preserve their guns.
Conditions within Yorktown were awful. Nowhere in the town was out of range of the allied guns – even Cornwallis was forced to live underground. Having had time to prepare, there was no shortage of food in the town, and the siege was too short for supplies to start to run low. The allies continued to tighten the siege. A second parallel, only 300 yards from the defences, was begun on 11 October. This parallel was very vulnerable at first. Cornwallis had saved his ammunition for just this moment and now ordered unrestricted firing, but over the next week the allied artillery battered down the British resistance. On 14 October a successful joint attack was launched on two British redoubts, which were quickly integrated into the second parallel. The allies were now in position to launch an assault on Yorktown.
At this late stage, Cornwallis finally took some action. On 15 October a raiding party broke into the second parallel and managed to spike six guns before retreating back to their lines. The next day, Cornwallis attempted to escape. The French and American forces besieging Gloucester were not as strong or as well dug in as those around Yorktown, so Cornwallis attempted to ship as many men as possible across the river to attempt a breakout. The weather intervened, making it impossible for enough troops to be ferried across quickly enough to gain surprise. Cornwallis had played his last card, and now prepared to negotiate.
The defeat at Yorktown broke the political will of Britain to continue the fight. No-one could see any route to eventual victory. Lord North’s government fell in March 1782. He was replaced by Lord Rockingham, who was determined to make peace, and restore good relations between Britain and the colonies. Although the fighting did not end immediately, the issue was no longer at doubt. A combination of French naval and land power, the American Continental army and Washington’s determination to strike a blow against the British had won one of the most decisive of all military victories.