The significance of the Treaty of Amity and Commerce between the U.S. and Japan, signed in 1858, lay in its role in establishing formal relations between the two countries, promoting trade and diplomatic relations. This treaty followed the forced opening of Japan by Commodore Matthew Perry in 1853, which ended Japan's isolationist policy. The treaty granted favorable trading conditions and extraterritorial rights for American citizens in Japan, impacting Japanese economic development. It marked a significant shift in Japan's international relations and contributed to the modernization of Japan, fostering Western influence and leading eventually to Japan's emergence as a global power.