Renewed relations with the West

In 1853, renewed contact with the West led directly to sweeping changes. That year, a small fleet of American naval vessels sailed into the bay south of Edo. The fleet's commander, Matthew C. Perry, asked Japan to open its ports to international trade.

The shogun rebuffed Perry, but Perry returned in 1854. After many discussions, Japan allowed the United States to station a negotiator, Townsend Harris, in the small port of Shimoda, far from Edo. In 1858, Harris succeeded in his negotiations on behalf of the United States, and Japan signed a treaty of commerce. The treaty permitted trade between the two countries, called for opening five Japanese ports to international commerce, and gave the United States the right of extraterritoriality. This right enabled American citizens to be governed only by U.S. laws while they were on Japanese soil.

Many Japanese disapproved of the treaty and similar agreements signed later. To them, the treaties were unequal, because Japan had granted extraterritoriality and other privileges that were not given to the Japanese in turn. The treaties enraged many samurai, who attacked and killed some foreign officials. The samurai also plotted to overthrow the shogunate.