1. On March 23, 1857, the Iowa Supreme Court ruled in the case of Ralph v. Brown that African Americans could not legally reside in the state. The ruling was later overturned by the Iowa General Assembly in 1868.

2. In 1905, a devastating tornado swept through the town of Audubon, Iowa on March 23, killing 10 people and causing significant damage to buildings and property.

3. March 23, 1929 marked the opening of Iowa's first liquid natural gas plant in Keokuk, Iowa. The plant served as a major source of energy for the state until it closed in the 1970s.

4. On March 23, 1990, Iowa Governor Terry Branstad issued a proclamation officially designating the oak tree as the state tree of Iowa.

5. In 2010, the Iowa State Cyclones men's basketball team upset the number one seeded University of Connecticut Huskies in the NCAA tournament on March 23. The victory marked one of the biggest upsets in tournament history and propelled the Cyclones to the Sweet Sixteen.