1. The first public demonstration of the telephone in Iowa took place on June 10, 1878, in Cedar Rapids. Alexander Graham Bell made a call to his assistant Thomas Watson in Boston, and the successful call was heard by delighted spectators.

2. On June 10, 1912, the first automatic sprinkler system was installed in Des Moines. A fire had recently destroyed an entire city block in the city, and the new invention was seen as a potential lifesaver.

3. In 1926, the Air Mail Act was passed, which led to the expansion of air mail delivery across the United States. On June 10 of that year, the first regular airmail service began in Iowa, flying from Des Moines to Omaha, Nebraska.

4. On June 10, 1942, Iowa native Merle Hay was the first soldier from the United States to die in World War II. He was killed in action on the island of Java, and a military base in Iowa was later named in his honor.

5. The first officially recognized LGBT pride parade in Iowa took place on June 10, 1970, in Des Moines. The event was held in response to the Stonewall riots in New York City the previous year and marked a turning point for the local gay rights movement.