1. Summer Solstice: June 21 marks the Summer Solstice in New Hampshire, which is the longest day of the year and the official start of summer. The day features the most daylight hours and the shortest night of the year in the northern hemisphere.

2. Statehood Anniversary: New Hampshire became the ninth state to join the Union on June 21, 1788, after ratifying the United States Constitution. The state was originally part of Massachusetts until it became a separate colony in 1679.

3. USS New Hampshire Launched: On June 21, 1905, the USS New Hampshire battleship was launched in Portsmouth, New Hampshire. The ship served in World War I and was eventually decommissioned in 1921.

4. Mount Washington Cog Railway: The Mount Washington Cog Railway, which is the world's first mountain climbing cog railway, opened on June 21, 1869. The railway transports tourists to the top of Mount Washington, the highest peak in New England.

5. Gunstock Ski Resort Founded: On June 21, 1937, the Gunstock Ski Club was founded in Gilford, New Hampshire. The ski club eventually became the Gunstock Mountain Resort and is now a popular ski destination in the state.