1. On April 18, 1775, Paul Revere's famous midnight ride began, warning people in Massachusetts and New Hampshire that the British were coming. This ride is considered one of the key events leading up to the Revolutionary War.

2. In 1837, the city of Nashua was incorporated, becoming the second-largest city in New Hampshire after Manchester. Nashua played an important role in the Industrial Revolution, with many textile mills and factories operating in the city.

3. On April 18, 1906, the Great New England Earthquake struck, with a magnitude of 5.5. Although the earthquake caused relatively little damage compared to the earthquake and fire that devastated San Francisco later that same day, it was still felt across much of New England and caused some minor damage.

4. In 1940, the New Hampshire Historical Society opened its new headquarters in Concord. The building, which was designed by famous architect Guy Lowell, is now listed on the National Register of Historic Places.

5. On April 18, 1997, New Hampshire's famous Old Man of the Mountain, a natural rock formation that had come to symbolize the state, collapsed. The formation had been slowly eroding for years, and efforts to save it had ultimately failed. Despite its collapse, the Old Man of the Mountain remains an important cultural icon in the state, and its image can still be found on many New Hampshire license plates and other official insignia.