What Happened on April 16?

April 16 remembers the 1947 Texas City industrial disaster — one of America's deadliest — and celebrates Emancipation Day in Washington, D.C., when enslaved people were freed in the capital eight months before the Emancipation Proclamation.

• 1862 — Congress frees enslaved people in Washington, D.C.

  President Abraham Lincoln signed the Compensated Emancipation Act on April 16, 1862, ending slavery in the nation's capital nearly nine months before the Emancipation Proclamation. Read the full story →

• 1943 — Swiss chemist Albert Hofmann accidentally discovers LSD's effects

  On April 16, 1943, chemist Albert Hofmann felt strange sensations after a tiny amount of lysergic acid diethylamide (LSD) touched his skin in a Swiss laboratory. Read the full story →

• 1947 — Explosion at Texas City devastates a Gulf Coast port

  A fire aboard the fertilizer ship SS Grandcamp ignited ammonium nitrate cargo on April 16, 1947, triggering a massive blast that killed hundreds and reshaped U.S. chemical safety rules. Read the full story →

• 1963 — Martin Luther King Jr. writes his Letter from Birmingham Jail

  While jailed for protesting segregation in Birmingham, Alabama, Dr. Martin Luther King Jr. drafted a powerful open letter on April 16, 1963, defending nonviolent civil rights action. Read the full story →

• 1972 — Apollo 16 launches toward the Moon's highlands

  NASA's Apollo 16 mission lifted off on April 16, 1972, sending astronauts John Young, Charles Duke, and Ken Mattingly to explore the Moon's rugged Descartes Highlands. Read the full story →

Famous birthdays

Charlie Chaplin (1889–1977) · Kareem Abdul-Jabbar (1947) · Selena Quintanilla-Pérez (1971–1995) · Martin Lawrence (1965)

Days & observances

Emancipation Day (Washington, D.C.) · National Eggs Benedict Day · National Stress Awareness Day · National Wear Your Pajamas to Work Day