1. On April 25, 1775, Paul Revere set out on his famous "midnight ride" to alert colonists in New Hampshire and other colonies of British troops approaching by sea. This ride helped kickstart the American Revolution.

2. April 25, 1783, marks the day when New Hampshire became the ninth state to ratify the Treaty of Paris, which officially ended the Revolutionary War and recognized America's independence from Great Britain.

3. In 1898, on April 25, the USS Maine Monument was dedicated in Portsmouth, New Hampshire. The monument commemorates the sailors who lost their lives when the USS Maine exploded in Havana Harbor, Cuba, igniting the Spanish-American War.

4. April 25, 1925, saw the opening of the Mount Washington Observatory in New Hampshire's White Mountains. This observatory conducts research and collects weather data, and is one of the most visited tourist attractions in the state.

5. On April 25, 1974, Portsmouth, New Hampshire, was declared a National Historic Landmark by the National Park Service in recognition of its well-preserved colonial architecture and heritage. Portsmouth is now a popular destination for tourists and history buffs alike.