On April 12, 1861, the Civil War began as Confederate forces opened fire on Fort Sumter in South Carolina.

In 1945, President Franklin D. Roosevelt died of a cerebral hemorrhage in Warm Springs, Georgia, at age 63; he was succeeded by Vice President Harry S. Truman.

In 1955, the Salk vaccine against polio was declared safe and effective.

In 1961, Soviet cosmonaut Yuri Gagarin became the first man to fly in space, orbiting the earth once before making a safe landing.

In 1963, civil rights leader Martin Luther King Jr. was arrested and jailed in Birmingham, Alabama, charged with contempt of court and parading without a permit. (During his time behind bars, King wrote his “Letter from Birmingham Jail.”)ADVERTISEMENT

In 1981, former world heavyweight boxing champion Joe Louis, 66, died in Las Vegas, Nevada.

In 1985, Sen. Jake Garn, R-Utah, became the first sitting member of Congress to fly in space as the shuttle Discovery lifted off.

In 1988, the U.S. Patent and Trademark Office issued a patent to Harvard University for a genetically engineered mouse, the first time a patent was granted for an animal life form.

In 1990, in its first meeting, East Germany’s first democratically elected parliament acknowledged responsibility for the Nazi Holocaust, and asked the forgiveness of Jews and others who had suffered.

In 1992, after five years in the making, Euro Disneyland (now called Disneyland Paris) opened in Marne-La-Vallee, France, amid controversy as French intellectuals bemoaned the invasion of American pop culture.

In 2015, Hillary Rodham Clinton jumped back into presidential politics, announcing in a video her much-awaited second campaign for the White House.

In 2018, police in Philadelphia arrested two black men at a Starbucks; the men had been asked to leave after one of them was denied access to the restroom. (Starbucks apologized and, weeks later, closed thousands of stores for part of the day to conduct anti-bias training.)

In 2020, Christians around the world celebrated Easter Sunday isolated in their homes by the coronavirus. St. Peter’s Square was barricaded to keep out crowds. Pope Francis celebrated Easter Mass inside the largely vacant basilica, calling for global solidarity in the face of the pandemic and urging political leaders to give hope and opportunity to people who had lost jobs.