1. In 1804, John Wentworth was inaugurated as the governor of New Hampshire. He served as governor for a total of 12 years, making him the longest-serving governor in the state's history.

2. On May 18, 1863, the 6th New Hampshire Volunteer Infantry Regiment participated in the Battle of Champion Hill during the American Civil War. The regiment suffered heavy casualties but played a crucial role in securing a Union victory.

3. The first public library in New Hampshire was founded on May 18, 1833, in the city of Dover. The Dover Public Library still serves the community to this day.

4. In 1929, the New Hampshire State House, located in Concord, was officially dedicated. The State House, which serves as the state's capitol building, is an impressive example of Greek Revival architecture.

5. On May 18, 1954, the United States Supreme Court issued its landmark decision in Brown v. Board of Education, which declared segregation in public schools to be unconstitutional. The ruling had a profound impact on the civil rights movement and paved the way for further progress towards racial equality in the United States.