On this day in 1906, a magnitude 7.9 earthquake struck San Francisco at 5:12 a.m. The quake and the fires it ignited killed over 3,000 people, destroyed 80% of the city, and left 225,000 homeless . #OTD #CaliforniaHistory #SanFrancisco #Earthquake1906 #HistoryTeacher

On this day in 1775, Paul Revere set out on his midnight ride from Boston to Lexington to warn colonial militias that British troops were on the march. His act of courage helped spark the opening of the American Revolution. #OTD #ThisDayInHistory #PaulRevere #AmericanRevolution #HistoryTeacher

On this day in 1987, the last 22 wild California Condors were captured for an emergency breeding program. The effort worked — condors now fly wild again in CA, AZ, and Baja California, with 500+ birds alive today. #OTD #CaliforniaHistory #Condor #HistoryTeacher

On this day in 1961, the CIA-backed Bay of Pigs invasion of Cuba failed completely. The botched operation became one of the Cold War's greatest embarrassments for the Kennedy administration and deepened U.S.-Soviet tensions. #OTD #BayOfPigs #ColdWar #HistoryTeacher

On this day in 1963, Dr. Martin Luther King Jr. wrote his "Letter from Birmingham Jail" while imprisoned for anti-segregation protests in Alabama. Written on scraps of paper, it became a defining document of the Civil Rights Movement. #OTD #MLK #CivilRights #HistoryTeacher

On this day in 1850, San Francisco was officially incorporated. Transformed almost overnight by the Gold Rush, it exploded from a tiny settlement into a booming city — becoming the West Coast's gateway to the world. #OTD #CaliforniaHistory #SanFrancisco #HistoryTeacher

On this day in 1947, Jackie Robinson took the field for the Brooklyn Dodgers — becoming the first African American in modern Major League Baseball. His courage helped break barriers far beyond the ballpark. #OTD #JackieRobinson #CivilRights #HistoryTeacher

On this day in 1939, John Steinbeck published The Grapes of Wrath. The novel follows Dust Bowl migrants seeking a better life in California — it won the Pulitzer Prize & helped expose the plight of migrant farmworkers. #OTD #CaliforniaHistory #Steinbeck #HistoryTeacher

On this day in 1865, President Lincoln was shot by John Wilkes Booth at Ford's Theatre in Washington, D.C. He died the next morning — just days after the Civil War effectively ended. #OTD #ThisDayInHistory #Lincoln #CivilWar #HistoryTeacher

On this day in 1860, the first Pony Express rider arrived in Sacramento, CA — 10 days after departing St. Joseph, MO. It transformed mail delivery to the West Coast at a time when the trip could take months. #OTD #CaliforniaHistory #PonyExpress #HistoryTeacher

On this day in 1743, Thomas Jefferson was born in Shadwell, VA. Author of the Declaration of Independence & 3rd U.S. President, he remains one of history's most influential Founding Fathers. #OTD #ThisDayInHistory #ThomasJefferson #HistoryTeacher