February 17 – The Armory Show opens in New York City. It displays the works of artists who are to become some of the most influential painters of the early twentieth century.
March 25 – Great Dayton Flood: Four days of rain in the Miami Valley flood the region and mark the worst natural disaster in Ohio's recorded history, killing over 360 people and destroying 20,000 homes, chiefly in Dayton.
April 26 – Mary Phagan is raped and strangled on the premises of the National Pencil Factory in Atlanta. Leo Frank is tried and convicted for the crime.
September 8 – The largest commercial office building in the world opens in Saint Louis, Missouri, to great fanfare. The Railroad Exchange building houses 31 acres under one roof, and its central tenant, Famous-Barr Co., becomes the world's largest department store with over 1,500,000 square feet.
September 19 – Francis Ouimet wins the U.S. Open (golf) championship by five strokes, becoming the first amateur to ever win the event.
December 1 – The Ford Motor Company introduces the first moving assembly line, reducing chassis assembly time from 12½ hours in October to 2 hours, 40 minutes (although Ford is not the first to use an assembly line, his successful adoption of one sparks an era of mass production).