Historical Events in September || Listed by Year

September has long been shaped by decisions and events that redefine nations and ideas. In 1787, delegates signed the U.S. Constitution. In 1862, Lincoln issued the Preliminary Emancipation Proclamation. More than a century later, Google was founded in 1998, helping launch the modern digital era.

Some Septembers bring political transformation. Others bring scientific advancement or cultural change. Across continents and centuries, the month reflects pivotal decisions, emerging technologies, and events that continue to influence global society.

Explore the full collection of Today in History events that occurred in September, or navigate directly to a specific day—from September 1 through September 30—to see what happened on this day in history.

Trace the timeline to uncover how September’s defining events continue to shape the world today.