1. On May 3, 1970, Ohio National Guardsmen opened fire on students at Kent State University, killing four and injuring nine others. The tragic incident sparked outrage and protests across the nation, leading to nationwide campus closures and a call for an end to the Vietnam War.

2. May 3, 1837 marked the infamous "Toledo War" between Ohio and Michigan. The dispute arose over the location of the state line, with both states laying claim to Toledo. The conflict ultimately ended in Ohio's favor with the signing of the Toledo Strip Treaty in 1836.

3. The first successful flight of a fixed-wing aircraft in Ohio took place on May 3, 1905. The Wright Brothers conducted a series of test flights in their homemade airplane at Huffman Prairie, near Dayton. The flight lasted approximately 29 seconds and covered a distance of 852 feet.

4. On May 3, 1937, the Ohio River flood peaked at a record-breaking 80 feet, causing widespread devastation across the state. Hundreds of thousands of homes and businesses were destroyed, and the flood resulted in 385 fatalities and $500 million in damages.

5. May 3, 2006 marked the grand opening of the Rock and Roll Hall of Fame and Museum's Library and Archives in Cleveland, Ohio. The facility houses a vast collection of music memorabilia and serves as a research center for scholars and music enthusiasts alike.