1. In 1970, the University of Iowa introduced the first ever electronic music composition program in the United States. It was created by composer James K. Randall and his team.

2. April 13, 1919 marks the day when over 400 coal miners in Knoxville, Iowa went on strike for better working conditions and wages. The strike lasted for four months until an agreement was reached in August.

3. In 1921, the Des Moines Register and Tribune became the first newspaper in Iowa to publish a crossword puzzle.

4. On April 13, 1936, the Iowa Supreme Court declared the state's minimum wage law unconstitutional. The law had been in place since 1933, but was challenged by business owners who felt it interfered with their ability to set their own wages for employees.

5. In 1964, Iowa native and future Hall of Fame baseball player Harmon Killebrew hit a home run at the first ever regular season game played at Metropolitan Stadium in Bloomington, Minnesota. The Vikings would go on to play there until 1981.