In 1775, the Patriots established the Continental Army as a defense force. The British Army returned in force in August 1776, and captured New York City, which became their base until the war ended in 1783. The British, using their powerful navy, could capture major ports, but 90% of the Americans lived in rural areas where they had full control. After the capture of a British invasion force moving down from Canada in the Saratoga campaign of 1777, France entered the war as an ally of the US, and added the Netherlands and Spain as French allies. Britain suffered casualties which it could not replace and had no major allies and few friends in Europe. The British strategy was then refocused on the South, where they expected large numbers of Loyalists would fight alongside the regulars. Far fewer Loyalists took up arms than Britain needed; royal efforts to control the countryside in the South failed. When the British army tried to return to New York, its rescue fleet was turned back by the French Navy and its army was captured by combined French-American forces under General George Washington at the Siege of Yorktown in October 1781. That effectively conceded American success. Opinion in Scotland often favoured the American cause, or criticised the poor performance of the British army.