1. On April 8, 1851, construction of the Johnson County Courthouse was completed. The courthouse, located in Iowa City, is still in use today and is listed on the National Register of Historic Places.

2. In 1864, the Battle of Pleasant Hill took place in Louisiana during the American Civil War. Iowa troops under General William Tecumseh Sherman fought in the battle, which resulted in a Union victory.

3. On April 8, 1913, Iowa became the first state in the nation to establish a state highway patrol. The patrol was initially created to enforce speed limits and reduce the number of traffic accidents on Iowa's roads.

4. In 1950, an F4 tornado struck the town of Redfield, Iowa, killing 13 people and causing significant damage. The tornado is still considered one of the worst in Iowa history.

5. On April 8, 1986, Iowa City was declared a UNESCO City of Literature, becoming the first city in the United States to receive the designation. The city is home to the University of Iowa's renowned Writers' Workshop, as well as numerous other literary organizations and events.