1. In 1868, the first telegraph line in Arizona Territory was established by the Western Union Telegraph Company, connecting Tucson and Yuma. This paved the way for faster communication and commerce in the region.

2. On July 28, 1914, Arizona Governor George W. P. Hunt called a special legislative session to ratify the 19th Amendment to the US Constitution, which granted women the right to vote. Arizona became one of the first states to ratify the amendment.

3. In 1929, the Hoover Dam, located on the border between Arizona and Nevada, began construction. Upon completion in 1936, the dam created Lake Mead, the largest reservoir in the United States.

4. President Lyndon B. Johnson signed the Wilderness Act into law on July 28, 1964, which designated certain protected areas in Arizona and other states as wilderness areas, preserving them for future generations.

5. In 2020, Arizona Governor Doug Ducey issued an executive order mandating the use of face masks in public spaces statewide, as COVID-19 cases surged. This order sparked controversy and backlash, with some citizens protesting against the mandate.