1. The first major tornado outbreak of the year in Minnesota occurred on April 21, 1967. A total of 25 tornadoes touched down throughout the state, causing widespread damage and claiming 13 lives.

2. In 1853, the first steam-powered ferryboat began operating across the Mississippi River between Minneapolis and St. Anthony. The ferry was a major milestone in the development of transportation infrastructure in the region.

3. On April 21, 1937, the Duluth Zoo opened to the public. The zoo featured a wide variety of animals, including lions, tigers, bears, and monkeys, and quickly became a popular destination in the region.

4. In 1924, the University of Minnesota's baseball team set a record for the most runs scored in a game by a Division I team. They defeated Northwestern 27-1 in a game played on April 21 of that year.

5. On April 21, 1862, the Dakota War of 1862 began with an attack by Dakota warriors on a group of white settlers near Acton, Minnesota. The conflict would last for several months, resulting in the deaths of hundreds of settlers and Dakota people and leading to the forced removal of the Dakota from Minnesota.