1. 1838: Iowa Territory Established - On April 26th, 1838, Iowa Territory was officially established by an act of Congress. Prior to this, Iowa was a part of the Wisconsin Territory.

2. 1865: The Battle of Camargo - The Battle of Camargo, a Civil War skirmish, took place in Benton County, Iowa on April 26th, 1865. Union troops successfully defeated Confederate soldiers and captured their supplies.

3. 1926: Iowa State Capitol Completed - After nearly 16 years of construction, the Iowa State Capitol building was completed on April 26th, 1926. The building, located in Des Moines, stands 275 feet tall and is one of the tallest domes in the United States.

4. 1951: University of Iowa Tragedy - On April 26th, 1951, a train collided with a bus carrying the University of Iowa's basketball team, killing four coaches and eight players. The tragedy is still remembered and honored today.

5. 1986: Chernobyl Disaster - Though not directly related to Iowa history, the Chernobyl nuclear disaster in Ukraine on April 26th, 1986 did have an impact on the state. Radioactive fallout from the disaster was detected in Iowa's milk supply months later, leading to increased regulation of nuclear power plants in the United States.