1. May 1, 1865, marks the day when Missouri officially abolished slavery. The Missouri Constitutional Convention met on that day and adopted a new state constitution that abolished slavery and declared all persons born in the state and subject to its jurisdiction as citizens.

2. May 1, 1961, is the day when the world's first successful spaceflight was carried out by Missouri-born astronaut, Alan Shepard. Shepard piloted the Freedom 7 spacecraft for a 15-minute suborbital flight that reached an altitude of 116 miles, becoming the first American to reach space.

3. May 1, 1977, saw the opening of the Gateway Arch in St. Louis, Missouri. The Arch is 630 feet high and is the tallest arch in the world, serving as a symbol for western expansion in the United States.

4. May 1, 1981, was the day when Missouri-born musician, Chuck Berry, became the first inductee into the Rock and Roll Hall of Fame. Berry was known for his unique guitar sound and style, and was a major influence on the development of rock and roll music.

5. May 1, 2017, marks the day when Eric Greitens, a former Navy SEAL, became the Governor of Missouri. Greitens served from 2017 to 2018, and was known for his conservative policies, including tax cuts and support for gun rights.