1. In 1882, the U.S. Post Office opened a new office in the town of Mesa, Arizona. This helped facilitate communication and commerce in the town, which had been incorporated just two years prior.

2. On March 22, 1890, the Arizona Territorial Legislature passed the first law regulating the use and sale of opium. The law required opium sellers to obtain a license and pay a fee, and prohibited the sale of opium to minors.

3. Arizona State University, located in Tempe, was founded on March 22, 1885 as the Arizona Territorial Normal School. Its original purpose was to train teachers for rural schools in the sparsely populated territory.

4. In 1935, the Hoover Dam was officially dedicated by President Franklin D. Roosevelt on March 22. The dam, located on the Colorado River between Arizona and Nevada, was a major engineering feat that helped provide water and electricity to the Southwest United States.

5. On March 22, 1963, the first professional basketball game was played in Tucson, Arizona. The Chicago Zephyrs (now the Washington Wizards) defeated the New York Knicks 97-91 in front of a crowd of over 7,000 spectators.