On April 30, 1789, George Washington is sworn in as the first American president and delivers the first inaugural speech at Federal Hall in New York City. Elements of the ceremony set tradition; presidential inaugurations have deviated little in the two centuries since Washington’s inauguration.

On April 30, 1859, the first chapter of Charles Dickens’ serialized novel, A Tale of Two Cities, is published in Dickens’ circular, All the Year Round. It rolls out over 31 weekly installments, with the last one appearing that November.

On April 30, 1897, British physicist J.J. Thomson announced his discovery that atoms were made up of smaller components. This finding revolutionized the way scientists thought about the atom and had major ramifications for the field of physics. Though Thomson referred to them as "corpuscles," what he found is more commonly known today as the electron.

On April 30, 1917, the so-called Battle of the Boot marks the end of the British army’s Samarrah Offensive, launched the previous month by Anglo-Indian forces under the regional commander in chief, Sir Frederick Stanley Maude, against the important Turkish railroad at Samarra, some 130 kilometers north of Baghdad, in Mesopotamia (modern-day Iraq).

On April 30, 1945, holed up in a bunker under his headquarters in Berlin, Adolf Hitler commits suicide by swallowing a cyanide capsule and shooting himself in the head. Soon after, Germany unconditionally surrendered to the Allied forces, ending Hitler’s dreams of a “1,000-year” Reich.

The South Vietnamese stronghold of Saigon (now known as Ho Chi Minh City) falls to People's Army of Vietnam and the Viet Cong on April 30, 1975. The South Vietnamese forces had collapsed under the rapid advancement of the North Vietnamese. The most recent fighting had begun in December 1974, when the North Vietnamese had launched a major attack against the lightly defended province of Phuoc Long, located due north of Saigon along the Cambodian border, overrunning the provincial capital at Phuoc Binh on January 6, 1975. Despite previous presidential promises to provide aid in such a scenario, the United States did nothing. By this time, Nixon had resigned from office and his successor, Gerald Ford, was unable to convince a hostile Congress to make good on Nixon’s earlier promises to rescue Saigon from communist takeover.

On April 30, 1977, more than 2,000 protesters occupy the Seabrook Nuclear Power Plant construction site in New Hampshire; 1,414 of these activists are arrested in what becomes one of the largest mass arrests in American history.

On April 30, 1997, at exactly 12:11 pm, London's iconic Big Ben clock stops ticking. For 43 minutes, the most famous clock in the world, which strikes the note of E every hour, failed to keep time.

On April 30, 2019, Japan’s 85-year-old Emperor Akihito steps down from the throne, becoming the first Japanese monarch to abdicate in over 200 years.