Issued in 1909, this postcard commemorates the 50th anniversary of the opening of Yokohama Port. It has a commemorative postmark marking the "Jubilee of Opening of Yokohama Port."
Yokohama Port was officially opened to foreign trade on July 1, 1859 in accordance with the US-Japan Treaty of Amity and Commerce.

The card honors Naosuke Ii and Commodore Matthew C. Perry. You could say that Japan-America relations started with these two men. Ii was the Tokugawa shogunate's Great Elder (Tairo) who favored and concluded commercial treaties with the Western powers and thus broke Japan's isolation from the world. Foreigners were then allowed to trade with Japan and take up residence in cities like Yokohama and Hakodate. Ii was later assassinated in 1860 by people who sought to oust the foreign "barbarians."

Commodore Perry first came to Japan in July 1853 with his four warships which the Japanese called "black ships" (kurobune). No diplomatic breakthrough was made, but Perry's knocking on Japan's door was heard loud and clear. Running low on provisions, Perry departed for China and promised to return to Japan which he did in Feb. 1854. This time he got what he wanted. The Treaty of Kanagawa was signed about a month later. The treaty allowed US ships to call on two ports: Shimoda (Kanagawa) and Hakodate (Hokkaido). Permission for a US Consul (Townsend Harris) to reside in Japan was also stipulated. Official diplomatic relations between Japan and America thus began.