After the surrender at Yorktown a situation developed that threatened relations between the new American nation and Britain. Following a series of retributive executions between Patriots and Loyalists, Washington, on May 18, 1782, wrote in a letter to General Moses Hazen that a British Captain would be executed for the execution of Joshua Huddy a popular patriot leader among volunteers, who was hung at the direction of Loyalist Captain Lippincott. Washington wanted Lippincott himself to be executed but was declined.
On the night of 21 May, two large earthquakes were followed by a collapse of the eastern flank of Mount Unzen's Mayuyama dome, causing a landslide which swept through the city of Shimabara and into Ariake Bay, triggering a great tsunami.