1. In 1895, the first-ever recorded baseball game in Arizona took place on April 6th. The game was played between Tempe Normal School (now Arizona State University) and the Phoenix Athletic Club.

2. On April 6th, 1909, the Arizona state legislature passed a bill that established the Arizona State Library. The bill allocated $3,000 for the construction and maintenance of the library, which was located in the state capitol building.

3. In 1917, the United States entered World War I, and on April 6th, the Arizona National Guard was mobilized for federal service. The Guard would go on to fight in several major battles, including the Meuse-Argonne Offensive.

4. In 1965, the first-ever Major League Baseball game was played in Arizona on April 6th. The game was part of a spring training tournament between the San Francisco Giants and the Kansas City Athletics, and it took place at Phoenix Municipal Stadium.

5. On April 6th, 1998, the Arizona Diamondbacks played their first-ever regular-season game. The game was played at Bank One Ballpark (now Chase Field) in Phoenix against the Colorado Rockies, and the Diamondbacks won 9-2. The team would go on to win the National League West division in their inaugural season.