April 12 (UPI) -- On this date in history:
In 1861, the Civil War began when Confederate troops opened fire on Fort Sumter in South Carolina.
In 1945, Franklin Delano Roosevelt, the longest-serving president in U.S. history, died of a cerebral hemorrhage at Warm Springs, Ga., three months into his fourth term. About 3 hours later, Vice President Harry S. Truman was sworn in as chief executive.
In 1955, U.S. health officials announced that the polio vaccine developed by Dr. Jonas Salk was "safe, potent and effective."
In 1961, Soviet cosmonaut Yuri Gagarin, in Vostok 1, became the first human to travel to outer space and the first to orbit Earth.
In 1975, the U.S. military evacuated Americans from the U.S. Embassy in Phnom Penh, Cambodia, as part of Operation Eagle Pull. The evacuation came as the communist Khmer Rouge seized the capital city to end a five-year war.
In 1976, Knopf published Anne Rice's debut novel, Interview with a Vampire, the first of a series of several books. The book was adapted into a movie starring Tom Cruise in 1994.
In 1981, the Columbia was launched on the first U.S. space shuttle flight. The crowd of more than 3,000 VIPs oohed-and-aahed, shouting, "Go Baby Go," and staring into the bright early morning sky long after Columbia was out of sight over the Atlantic Ocean.
In 2002, Venezuelan President Hugo Chavez was overthrown in a military coup. He was returned to office two days later riding a wave of public sentiment.
In 2003, Gen. Amir al-Saadi, Saddam Hussein's top science adviser, denied Iraq had any weapons of mass destruction and surrendered to U.S. forces.
In 2007, Kurt Vonnegut Jr., whose novels such as Slaughterhouse-Five resonated with a generation, died in New York at the age of 84.
In 2009, U.S. Navy SEALs rescued a U.S. ship captain, Richard Phillips, held hostage by pirates off the Somalia coast, by killing three of the kidnappers four days after the standoff began. The incident inspired the 2013 Tom Hanks movie, Captain Phillips.
In 2012, North Korea, defying international warnings, fired a long-range test rocket but the launch ended in failure. U.S. officials said the rocket broke up and fell into the sea.
In 2014, pro-Russian gunmen seized police stations and other facilities in an escalating crisis in eastern Ukraine.