1. In 1867, the first territorial government of Arizona was established, with John N. Goodwin appointed as its first governor. This marked an important milestone in Arizona's development and helped lay the foundation for future growth and progress.

2. In 1905, the Roosevelt Dam was completed, becoming the largest masonry dam in the world at the time. The dam provided much-needed irrigation and hydropower to the region, helping to fuel Arizona's agricultural and industrial growth.

3. In 1919, The Grand Canyon National Park was officially established, protecting one of Arizona's most iconic and breathtaking natural landmarks. Today, the park draws millions of visitors each year, offering unparalleled views and outdoor adventures.

4. In 1987, Arizona became the last state in the US to observe Martin Luther King Jr. Day as a state holiday. This came after years of controversy and protest, with many arguing that the state government was not doing enough to honor Dr. King's legacy.

5. In 2013, the Yarnell Hill fire broke out in Yavapai County, ultimately claiming the lives of 19 firefighters. The tragedy shocked the state and the nation, highlighting the dangers faced by those who risk their lives to protect others from natural disasters and emergencies.