Which treaty in 1854 opened Japanese ports to foreign trade?

The treaty that opened Japanese ports to foreign trade in 1854 was the Treaty of Kanagawa, also called the Convention of Kanagawa.

Signed on March 31, 1854, between the United States and Japan’s Tokugawa shogunate, it opened Shimoda and Hakodate to American ships. It also promised humane treatment for shipwrecked American sailors and allowed the United States to establish a consul in Japan.

The agreement followed Commodore Matthew Perry’s 1853–54 expeditions, which used naval pressure to challenge Japan’s long-standing policy of restricted foreign contact. It did not create unrestricted commerce: a broader commercial treaty, the Harris Treaty, followed in 1858.

A common mix-up is the Treaty of Portsmouth, which ended the Russo-Japanese War in 1905, or the Treaty of Shimonoseki, which ended the First Sino-Japanese War in 1895. The Treaty of Nanking instead concerned China and Britain in 1842.