1. On May 15, 1869, the first telegraph line was completed in Alaska. The line ran from Sitka to Wrangell and connected the territory to the rest of the United States.

2. In 1884, a major earthquake struck Alaska on May 15. The earthquake, which had a magnitude of 7.9, was centered near Sitka and caused widespread damage and landslides.

3. On May 15, 1912, the first airplane flight in Alaska took place. A pilot named Charles J. Coxey flew a Curtiss Model D biplane over Anchorage for 15 minutes, marking the start of aviation in the state.

4. May 15, 1926, marked the official opening of the Alaska Railroad. The railroad, which was built by the government to connect Anchorage with the port of Seward, helped to develop the interior of the state and played a key role in World War II.

5. In 1987, on May 15, the Exxon Valdez oil spill occurred in Prince William Sound. The spill, which was caused by a tanker hitting a reef, released over 11 million gallons of crude oil into the ocean and had devastating effects on the local environment and economy.