Among the many crises that beset Edo, and Japan as a whole, one that truly changed the course of history was the arrival of the Black Ships. At the end of the 18th century, foreign ships started to showing up in the waters off Japan. Then in 1853, a fleet of four U.S. naval ships led by Commodore Matthew Perry of the East India Squadron arrived in Uraga, seeking to trade with Japan. They left Edo Bay promising to return the following year. In order to strengthen Edo Bay's coastal defenses, in August 1853 the shogunate government set to work constructing a series of gun batteries (o-daiba) along the Shinagawa coast, completing them in April 1854. The shogunate had planned to construct 12 of these batteries altogether (11 were originally planned, with one added later), but this plan was altered owing to insufficient funds, and only six were ever completed.

There is a famous ironic verse which goes “Awoken from sleep / of a peaceful quiet world / by Jokisen tea; / with only four cups of it / one can’t sleep even at night” (the four cups of Jokisen tea has a double entendre referring to the four black steam ships). The reason why people became panic-stricken is because this Perry's squadron appeared in the Uraga channel near Edo and there was a rumor that they would fire upon Edo. Various types of prints made by kawaraban (news broadsheets) became widespread among Edo residents.

The Tokugawa Shogunate was eventually compelled by Perry’s firm stance to conclude the Convention of Kanagawa (Nichibei Washin Jôyaku) and then the Japan-US Treaty of Amity and Friendship or Kanagawa Treaty (Kanagawa Jôyaku) in 1854 (the 1st year of Ansei era). Similar treaties were subsequently concluded with the United Kingdom (Anglo-Japanese Friendship Treaty), the Russians (Treaty of Shimoda), and the French (Treaty of Amity and Commerce between France and Japan), all of which opened up Japan bringing to an end the many years of Japan’s policy of national isolation. These five treaties are collectively called the "Ansei Five-Power Treaties" (Ansei Gokakoku Jôyaku).