Excerpts from Books and Wikipedia
"Before Commodore Perry's squadron of four warships, including two paddle steamers, menacingly entered Tokyo Bay, with the steamships pouring out such volumes of black smoke that frightened Japanese on shore thought they looked like floating volcanoes, the government of Japan had kept the country firmly closed to foreigners. . . . Perry was sent to demand a treaty that would open up commercial and political relations with America. . . . But the Japanese would not accept a treaty and Perry withdrew with a promise to return. He kept the promise, returning the following February with a larger squadron of warships. . . . The Japanese authorities, overawed and divided, signed the Treaty of Kanagawa in March 1854, which gave the United States most-favored status as a trading nation, opened two ports as coaling stations, and guaranteed the safe return of shipwrecked American seamen." [Furtado: 1001 Days]