April 15th

Two bombs exploded at the Boston Marathon in Boston, Massachusetts, killing 3 and injuring at least 170 others.
Boston Marathon bombing
Retired Supreme Court Justice Byron R. White died at age 84.
Byron White
Cal Ripken Jr. of the Baltimore Orioles became the 24th major league player to reach 3,000 hits.
2000 Major League Baseball season
Pol Pot, leader of the Camobodia's brutal Khmer Rouge regime, died at age 73.
History of Cambodia
The 100th Boston Marathon was won by Moses Tanui of Kenya.
Moses Tanui
The World Trade Organization is founded. The WTO coordinates and strives to liberalize international trade. It has been criticized for ignoring and escalating the negative social and environmental side-effects of globalization.
World Trade Organization
A small group of students initiates pro-democracy protest on Tiananmen Square in Beijing. The death of reformer Hu Yaobang triggered the demonstrations, which grew in size and were brutally dispersed in the Tiananmen Square Massacre on June 4.
Talk:Tiananmen Square protests of 1989/Archive 1
The United States launches retaliatory air strikes against Libya. Around 40 Libyan died in Operation El Dorado Canyon, including an infant girl. The attack was the United States' response to the bombing of a Berlin discotheque on April 5, in which 3 people had died.
1986 United States bombing of Libya
Existentialist philosopher Jean-Paul Sartre died in Paris at age 74.
Jean-Paul Sartre
Ray Kroc acquired McDonald's and opened his first restaurant in Des Plaines, Ill., today the official McDonald’s Corporate Museum.
History of McDonald's
Jackie Robinson made his Brooklyn Dodger debut and scored the game-winning run. On April 15, 1997, his number, 42, was retired.
Jackie Robinson
The German concentration camp Bergen-Belsen is liberated. British and Canadian troops found about 53,000 prisoners inside the camp. Tens of thousands died before and after the liberation.
Bergen-Belsen concentration camp
The Eastman Kodak Company launches Kodachrome. The photographic film was one of the most popular media used by professional and hobby photographers around the world. The product was discontinued in 2009 because of the advent of digital photography.
A paymaster and guard were murdered in Braintree, Mass. Sacco and Vanzetti were accused of the crime.
Sacco and Vanzetti
Titanic sank off the coast of Newfoundland on its maiden voyage after it struck an iceberg.
RMS Titanic
First modern Olympic games close in Athens, Greece.
1896 Summer Olympics
1st telephone installed: Boston-Somerville in Massachusetts.
Charles Williams Jr. House
President Abraham Lincoln died nine hours after being shot by John Wilkes Booth at Ford's Theater in Washington. Andrew Johnson became the 17th president.
Assassination of Abraham Lincoln
President Abraham Lincoln declared a state of insurrection and called out Union troops three days after the Confederate attack on Fort Sumter in South Carolina.
President Lincoln's 75,000 volunteers
The city of San Francisco was incorporated.
San Francisco
Thomas Hopkins Gallaudet opened the first free American school for the deaf in Hartford, Conn.
American School for the Deaf
Samuel Johnson's "A Dictionary of the English Language" published in London.
A Dictionary of the English Language