On April 12, 1633, chief inquisitor Father Vincenzo Maculani da Firenzuola, appointed by Pope Urban VIII, begins the inquisition of physicist and astronomer Galileo Galilei. Galileo was ordered to turn himself in to the Holy Office to begin trial for holding the belief that the Earth revolves around the sun, which was deemed heretical by the Catholic Church. Standard practice demanded that the accused be imprisoned and secluded during the trial.

During the American Civil War, Major General Nathan Bedford Forrest’s Confederate raiders attack the isolated Union garrison at Fort Pillow, Tennessee, overlooking the Mississippi River. The fort, an important part of the Confederate river defense system, was captured by federal forces in 1862. Of the 500-strong Union garrison defending the fort, more than half the soldiers were African Americans.

On April 12, 1945, President Franklin Delano Roosevelt passes away partway through his fourth term in office, leaving Vice President Harry S. Truman in charge of a country still fighting the Second World War and in possession of a weapon of unprecedented and terrifying power.

On April 12, 1954, Bill Haley and His Comets record “(We’re Gonna) Rock Around The Clock.” If rock and roll was a social and cultural revolution, then “(We’re Gonna) Rock Around The Clock” was its Declaration of Independence. And if Bill Haley was not exactly the revolution’s Thomas Jefferson, it may be fair to call him its John Hancock.

On April 12, 1963, Good Friday, the Rev. Dr. Martin Luther King Jr., is arrested and jailed for a campaign of protests, marches and sit-ins against segregation in Birmingham, Alabama. The actions, orchestrated with his Southern Christian Leadership Conference and their partners in the Alabama Christian Movement for Human Rights, had begun a little over a week earlier, on April 3.

The space shuttle Columbia is launched from Cape Canaveral, Florida, becoming the first reusable manned spacecraft to travel into space. Piloted by astronauts Robert L. Crippen and John W. Young, the Columbia undertook a 54-hour space flight of 36 orbits before successfully touching down at California’s Edwards Air Force Base on April 14.

The Soviet government officially accepts blame for the Katyn Massacre of World War II, when nearly 5,000 Polish military officers were murdered and buried in mass graves in the Katyn Forest. The admission was part of Soviet leader Mikhail Gorbachev’s promise to be more forthcoming and candid concerning Soviet history.