Hugo O'Conor, the founding father of Tucson, Arizona, authorized the construction of a military fort, Presidio San Agustín del Tucsón, on August 20, 1775, near the base of what is now known as "A" mountain. During the Spanish period of the presidio, attacks such as the Second Battle of Tucson were repeatedly mounted by the Apache.

Tucson is commonly known as "The Old Pueblo". While the exact origin of this nickname is uncertain, it is commonly traced back to Mayor R. N. "Bob" Leatherwood. When rail service was established to the city on March 20, 1880, Leatherwood celebrated the fact by sending telegrams to various leaders, including the President of the United States and the Pope, announcing that the "ancient and honorable pueblo" of Tucson was now connected by rail to the outside world.

With 350 days of sunshine a year, Tucson is the sunniest city in the United States.

Whether the Hohokam were politically unified isn't clear. Hohokam culture may have just involved unrelated neighboring communities working together to survive their harsh desert environment.

The city is built along the Santa Cruz River, formerly a perennial river. Now a dry river bed for much of the year, it regularly floods during significant seasonal rains.

Frank Stilwell was closely involved in the events leading up to the Gunfight at the O.K. Corral on October 26, 1881, and was suspected in the murder of Morgan Earp on March 18, 1882. Two days after Morgan's death, Stilwell was gunned down in a Tucson train yard. Arrest warrants were issued for Deputy U.S. Marshal Wyatt Earp and four others, including Doc Holliday. Earp agreed to turn himself in but instead fled the Arizona Territory for Colorado. Late in his life, Wyatt Earp admitted to killing Stilwell at close range with a shotgun.

El Charro Café is the oldest Mexican restaurant in the U.S. continuously operated by the same family. It may also be the birthplace of the chimichanga. As the legend goes, this deep-fried dish was invented by Monica Flin, who established El Charro in 1922, when she accidentally flipped a burrito into the fryer, splattering oil everywhere. Since kids were within earshot, she resisted the urge to curse, instead yelling "chimichanga", a slang word that means thingamajig.

Mission San Xavier del Bac was established in 1692 by Father Eusebio Francisco Kino, who founded a chain of Spanish missions in the Sonoran Desert. Unlike the other Spanish missions in Arizona, San Xavier is still actively run by Franciscans, and continues to serve the native community by which it was built. Widely considered to be one of the finest examples of Spanish Colonial architecture in the United States, the Mission hosts some 200,000 visitors each year.

Eegee's is a chain of restaurants in greater Tucson, as well as one in Casa Grande, Arizona. It specializes in sub sandwiches and is most famous for its frozen fruit drink, called the "eegee." It was founded in 1971 by Edmund Irving and Robert Greenberg, who combined their initials ("E" from Edmund and "G" from Greenberg) to create the name "eegee's."

In 1863, the U.S. Congress made Arizona a U.S. territory. The first capital was Fort Whipple. In May 1864, the territorial capital was moved to Prescott. Tucson served as the capital from 1867 to 1877. In 1877, the capital moved back to Prescott. Finally, Phoenix was declared the permanent capital on February 4, 1889.