May 22, 1455: The first battle in the 30-year <a href="/ce6/history/A0842431.html">War of Roses</a> took place at St. Albans.
May 22, 1761: The first <a href="/ipd/A0516406.html">life insurance</a> policy in the United States was issued in Philadelphia.
May 22, 1849: <a href="/node/62942">Abraham Lincoln</a> received patent number 6469 for his floating dry dock.
May 22, 1927: An <a href="/node/10097">earthquake</a> near Xining, <a href="/node/70469">China</a>, measuring 8.3 claimed approximately 200,000 victims.
May 22, 1947: <a href="/node/155738">Harry S. Truman's</a> Doctrine brought aid to <a href="/node/70501">Greece</a> and <a href="/node/70602">Turkey</a> to combat the spread of <a href="/ce6/history/A0813068.html">Communism</a>.
May 22, 1972: <a href="/node/155742">Richard Nixon</a> arrived in Moscow, becoming the first U.S. president to visit the Soviet Union.
May 22, 1990: North Yemen and South Yemen merged to form the <a href="/node/70624">Republic of Yemen</a>.
May 22, 1992: <a href="/node/61014">Johnny Carson</a> hosted the last episode of his <i>Tonight Show</i>.
May 22, 2003: The <a href="/node/10091">UN Security Council</a> approved a resolution lifting the economic sanctions against <a href="/node/70514">Iraq</a> and supporting the U.S.-led administration in Iraq.
May 22, 2011: At least 140 people are killed and hundreds more injured as a three-quarter-mile-wide tornado hits Joplin, Missouri. The tornado is among the deadliest in the nation's history, destroying nearly a third of the city and damaging about 2,000 buildings, including water treatment and sewage plants.
May 22, 2012: Tokyo Skytree, which at 634 meters high is the tallest tower in the world, opened to the public.
More events from This Day in History: May 22