On July 8, 1853, Commodore Matthew Perry of the United States Navy, commanding a squadron of two steamers and two sailing vessels, sailed into Tôkyô harbor aboard the frigate Susquehanna<span>. Perry, on behalf of the U.S. government, forced Japan to enter into trade with the United States and demanded a treaty permitting trade and the opening of Japanese ports to U.S. merchant ships. This was the era when all Western powers were seeking to open new markets for their manufactured goods abroad, as well as new countries to supply raw materials for industry. It was clear that Commodore Perry could impose his demands by force. The Japanese had no navy with which to defend themselves, and thus they had to agree to the demands.