ere killed in a single morning on 29 May 1945 in what is now known as the Great Yokohama Air Raid, when B-29s firebombed the city and in just one hour and nine minutes reduced 42% of it to rubble.
During the Korean War, the United States Navy used Yokohama's port as a transshipment base. This ship departed Yokohama in 1951, carrying war dead home to the U.S.
During the American occupation, Yokohama was a major transshipment base for American supplies and personnel, especially during the Korean War. After the occupation, most local U.S. naval activity moved from Yokohama to an American base in nearby Yokosuka.
The city was designated by government ordinance on September 1, 1956.
The city's tram and trolleybus system was abolished in 1972, the same year as the opening of the first line of Yokohama Municipal Subway.
Construction of Minato Mirai 21 ("Port Future 21"), a major urban development project on reclaimed land, started in 1983. Minato Mirai 21 hosted the Yokohama Exotic Showcase in 1989, which saw the first public operation of maglev trains in Japan and the opening of Cosmo Clock 21, then the tallest Ferris wheel in the world. The 860m-long Yokohama Bay Bridge opened in the same year.
In 1993, Minato Mirai saw the opening of the Yokohama Landmark Tower, the tallest building in Japan.
The 2002 FIFA World Cup final was held in June at the International Stadium Yokohama.
In 2009, the city marked the 150th anniversary of the opening of the port and the 120th anniversary of the commencement of the City Administration. An early part in the commemoration project incorporated the Fourth Tokyo International Conference on African Development (TICAD IV) which was held in Yokohama in May 2008.
In November, 2010, Yokohama hosted the Asia-Pacific Economic Cooperation (APEC) meeting
