Born into an aristocratic family with a history of public service, Cornwallis was politically opposed to the war, but agreed to serve when it became clear that Britain would require a significant military presence in the Thirteen Colonies. First arriving in May 1776, he participated in the Battle of Sullivan's Island, before joining the main army under General William Howe. He played a notable role in the partially successful New York and New Jersey campaign when George Washington successfully eluded him after the Battle of the Assunpink Creek and inflicted a decisive defeat on troops left at his rear in the Battle of Princeton.