1. On April 4, 1906, the Alaska-Canadian Boundary Tribunal issued its final decision, settling a long-standing dispute over the boundary between Alaska and Canada. The decision established the border between the two countries, and was later approved by the governments of both nations.

2. In 1968, a 9.2 magnitude earthquake struck Alaska on April 4, causing massive damage and triggering a tsunami that devastated coastal communities. The quake, which lasted approximately four and a half minutes, remains one of the largest ever recorded.

3. On April 4, 1942, Japanese forces launched an air raid on the U.S. naval base at Dutch Harbor, Alaska. The attack marked the first time that enemy forces had attacked American soil since the War of 1812, and proved to be a precursor to the larger Battle of Attu that would take place later that year.

4. In 1985, the oil tanker Arco Anchorage ran aground near the port of Valdez, Alaska, spilling approximately 940,000 gallons of crude oil into the Prince William Sound. The incident led to widespread environmental damage, and remains one of the worst oil spills in U.S. history.

5. On April 4, 1929, the world's first commercial air service to Alaska began when Northwest Airways began flying airmail from Minneapolis to Seattle, with stops in North Dakota and Montana. The service would eventually expand to include passenger flights, opening up Alaska to tourism and economic development.