1. In 1856, the Sacking of Lawrence occurred on May 3. A pro-slavery group attacked the town of Lawrence, Kansas, which was considered a stronghold of anti-slavery sentiment in the region. The attack was one of several violent incidents that occurred during the period known as "Bleeding Kansas" in the lead-up to the American Civil War.

2. In 1913, the first airplane flight in Kansas took place on May 3. The flight was made by Clyde Cessna in a monoplane he had built himself. Cessna would later go on to found the Cessna Aircraft Company, which became a major manufacturer of general aviation aircraft.

3. On May 3, 1968, a tornado outbreak occurred in Kansas and several other Midwestern states. The outbreak produced several strong tornadoes, including an F4 tornado that struck the city of Salina, causing significant damage.

4. In 1999, the Kansas City Wizards (now known as Sporting Kansas City) played their inaugural home game at Arrowhead Stadium on May 3. The Wizards were a professional soccer team that competed in Major League Soccer (MLS) until 2010, when they moved to their own stadium, now known as Children's Mercy Park.

5. On May 3, 2007, a shooting occurred at the Ward Parkway Center shopping mall in Kansas City. The shooter, identified as 22-year-old David W. Logsdon, killed two people and injured several others before turning the gun on himself. The incident prompted renewed discussion of gun violence and mass shootings in the United States.