Events of the 20th Century

Albert Einstein determined that the laws of physics are the same for all non-accelerating observers and that the speed of light in a vacuum was independent of the motion of all observers. This was the theory of special relativity.

The eastern front was between Germany, Austria-Hungary, and Bulgaria on one side and Russia and Romania on the other. Although there were a number of causes for the war, the assassination of Austrian Archduke Franz Ferdinand was the main event that started the war.

The Roaring '20s were a time of a booming stock market, speakeasies, short skirts, the Charleston, and jazz. The '20s also showed great strides in women's suffrage (women getting to vote) in 1920.

The Great Depression was the worst economic downturn in US history. It began in 1929 and did not abate until the end of the 1930s. The stock market crash of October 1929 signalled the beginning of the Great Depression. By 1933, unemployment was at 25 per cent and more than 5,000 banks had gone out of business.

World War II, also called the Second World War, the conflict that involved virtually every part of the world during the years 1939–45. The principal belligerents were the Axis powers—Germany, Italy, and Japan—and the Allies—France, Great Britain, the United States, the Soviet Union, and, to a lesser extent, China.

Sometime between 1946 and 1950, the research staff of RCA Laboratories invented the world's first electronic, color television system. A successful color television system based on a system designed by RCA began commercial broadcasting on December 17, 1953.

The Vietnam War was a long, costly and divisive conflict that pitted the communist government of North Vietnam against South Vietnam and its principal ally, the United States. The conflict was intensified by the ongoing Cold War between the United States and the Soviet Union.

On November 18, 1978, in what became known as the “Jonestown Massacre,” more than 900 members of an American cult called the Peoples Temple died in a mass suicide-murder under the direction of their leader Jim Jones.

On March 24, 1989, the tanker Exxon Valdez grounded on Bligh Reef in Alaska's Prince William Sound, rupturing its hull and spilling nearly 11 million gallons of Prudhoe Bay crude oil into a remote, scenic, and biologically productive body of water.

The Columbine High School massacre was a school shooting and attempted bombing that occurred on April 20, 1999, at Columbine High School in Columbine, Colorado, United States. The perpetrators, twelfth grade (senior) students Eric Harris and Dylan Klebold, murdered 12 students and one teacher. Ten students were killed in the school library, where the pair subsequently committed suicide. 21 additional people were injured with gunshots and gunfire was also exchanged with the police. Another three people were injured trying to escape the school. At the time, it was the deadliest school shooting in United States history.