1. In 1917, Alaska officially became a territory of the United States, as the Organic Act passed by Congress was signed into law on August 12 of that year. This act established a government for the territory and granted Alaskans more political representation.

2. In 1943, the construction of the Alaska-Canada Military Highway (ALCAN) was completed on August 12. The highway was built during World War II to serve as a supply line to transport troops and goods from Alaska to the Lower 48.

3. On August 12, 1972, a devastating earthquake with a magnitude of 6.4 struck the city of Sitka. The quake caused significant damage to buildings and infrastructure but there were no fatalities reported.

4. In 1980, the Mt. Edgecumbe High School Tidal Wave Disaster occurred on August 12. A prankster lit hundreds of old tires on fire in the shape of an arrow pointing towards the dormant volcano, Mt. Edgecumbe. The prank caused a false tsunami warning which evacuated the city, only to find that the smoke spell an arrow pointing to the prankster's handiwork.

5. On August 12, 2010, the U.S. government finally agreed to pay $193 million in compensation to Alaska Natives for land that had been taken from them by the federal government during the early 20th century. The settlement was the result of a lawsuit that had been filed in 1994, and it was the largest single settlement in the history of the Alaska Native claims settlement.