From Historynet: Today in History March 18

37               The Roman Senate annuls Tiberius'  will and proclaims Caligula  emperor.

1692          William Penn  is deprived of his governing powers.

1863          Confederate women riot in Salisbury, N.C. to protest the lack of flour and salt in the South.

1865          The Congress of the Confederate States of America adjourns for the last time.

1874          Hawaii signs a treaty giving exclusive trading rights with the islands to the United States.

1881          Barnum and Bailey's Greatest Show on Earth opens in Madison Square Gardens.

1911          Theodore Roosevelt  opens the Roosevelt Dam in Phoenix, Ariz., the largest dam in the United States to date.

1913          Greek King George I  is killed by an assassin. Constantine I  is to succeed.

1916          On the Eastern Front, the Russians counter the Verdun assault with an attack at Lake Naroch. The Russians lose 100,000 men and the Germans lose 20,000.

1917          The Germans sink the U.S. ships, City of Memphis, Vigilante and the Illinois, without any type of warning.

1922          Mahatma Gandhi  is sentenced to six years in prison for civil disobedience in India.

1939          Georgia finally ratifies the Bill of Rights, 150 years after the birth of the federal government. Connecticut and Massachusetts, the only other states to hold out, also ratify the Bill of Rights in this year.

1942          The third military draft begins in the United States.

1943          American forces take Gafsa in Tunisia.

1943          Adolf Hitler  calls off the offensive in the Caucasus.

1944          The Russians reach the Romanian border.

1950          Nationalist troops land on the mainland of China and capture Communist-held Sungmen.

1953          The Braves baseball team announces that they are moving from Boston to Milwaukee.

1965          Cosmonaut Alexei Leonov  becomes the first man to spacewalk when he exits his Voskhod 2 space capsule while in orbit around the Earth.

1969          President Richard M. Nixon  authorizes Operation Menue, the 'secret' bombing of Cambodia.

1970          The U.S. Postal Service is paralyzed by the first postal strike.

1971          U.S. helicopters airlift 1,000 South Vietnamese soldiers out of Laos.

1975          South Vietnam abandons most of the Central Highlands to North Vietnamese forces.

1977          Congo President Marien Ngouabi  is killed by a suicide commando.

1981          The United States discloses biological weapons tests in Texas in 1966.

1986          Buckingham Palace announces the engagement of Prince Andrew  to Sarah Ferguson .