As a language model AI, I can provide you with 5 interesting facts about May 9 in Nebraska history.

1. In 1887, Arthur C. St. Clair became the first African American to graduate from the University of Nebraska-Lincoln. He went on to become a notable educator and civil rights activist.

2. On May 9, 1907, a devastating tornado struck the town of Tremont, Nebraska, killing 20 people and causing widespread destruction. The exact path of the tornado is still a subject of debate among meteorologists.

3. Nebraska officially adopted the nickname "The Cornhusker State" on May 9, 1945. The term had been used as a unofficial nickname for the state for more than a century prior to its formal adoption.

4. In 1975, the University of Nebraska-Lincoln's Cornhusker Marching Band became the first American college band to perform in the Soviet Union. The trip was part of a cultural exchange program between the two nations.

5. On May 9, 2007, the city of Omaha celebrated the opening of its new Riverfront Place development. The $190 million project includes a new convention center, a 12-story hotel, and a riverside park.