1. In 1813, the town of Berlin, New Hampshire was incorporated on April 23, named after the capital city of Germany. The town became a significant center for logging and paper mills in the 19th and 20th centuries.

2. On April 23, 1889, the New Hampshire College of Agriculture and the Mechanic Arts (now known as the University of New Hampshire) was authorized by the state legislature.

3. In 1905, the New Hampshire state flag was officially adopted on April 23. The flag features the state seal on a blue background and was designed by a group of women from the Daughters of the American Revolution.

4. The Mount Washington Observatory, located on the summit of Mount Washington, was founded on April 23, 1932. The observatory conducts research and collects weather data, and is known for having some of the most extreme weather conditions in the world.

5. On April 23, 2005, New Hampshire became the first state in the United States to offer civil unions to same-sex couples. The law granted same-sex couples many of the rights and benefits of marriage, although it was not considered equal to marriage under federal law until the Supreme Court's decision in 2015.