1854: Gadsden Purchase

The Tucson Presidio was part of the 29,670-square-mile swath acquired for $10 million from Mexico — primarily to build a southern transcontinental railroad line. Arizona became a separate U.S. territory in 1863 and, after a contentious political process, finally gained statehood in 1912.

1880: The railroad arrives

Tucson was the territory’s largest community with 7,000 residents when the Southern Pacific brought new goods and people, including U.S. President Rutherford B. Hayes. Tucson freight company owner Estevan Ochoa introduced territorial legislation in 1877 to facilitate the railroad’s completion.

1891: University of Arizona opens

Many Tucsonans wanted the territorial capital back, a designation lost to Prescott in 1877. Instead, the 1885 Arizona legislature awarded the Old Pueblo a university, a decision that left some residents extremely disgruntled. Six years later, the first classes were held in the building now known as “Old Main.”

1920: Tucson loses “Metropolis of Arizona” status

For 66 years, Tucson was the largest community in Arizona. Because of greater water supplies, more agriculture and several other reasons, Phoenix zoomed ahead in population by 1920. In response, Tucson businesses established the Sunshine Climate Club to bring health seekers and tourists to town.

1922: Urban lifestyle gets its start

Some real estate agents credited best-selling author Harold Bell Wright with initially seeing the attractiveness of low-density desert living that helped inspire “sprawl” in the valley. He purchased 160 acres of remote property at the southeast corner of Speedway and Wilmot Road and built a home where he lived for almost a decade. In 1950 Wright’s property became the subdivision bearing his name.

1923: Steward Observatory opens on the UA campus

The building with a 36-inch telescope, first proposed by noted scientist Andrew Ellicott Douglass in 1916, was delayed in part because of World War I. Funded by Lavinia Steward, it helped focus attention on Tucson and by 1967 the community was labeled “the astronomy center of the world.”

1927: Airport moves to Davis-Monthan

Tucson opened the first municipally owned airport in the United States in 1919 on South Sixth Avenue where the rodeo grounds are now. Within a few years planes were too big and more space was needed. On Sept. 23, 1927, four months after flying solo across the Atlantic Ocean, Charles Lindbergh flew in to dedicate the new Davis-Monthan airfield.

1933: Designation of Saguaro National Monument (east)

Efforts to protect Tucson’s magnificent natural setting included the establishment of the Desert Botanical Laboratory on Tumamoc Hill in 1902 and creation of Tucson Mountain Park in 1929. Setting aside saguaro-covered rolling terrain on Tucson’s east side was a goal of UA President Homer L. Shantz and many others. It was finally accomplished on March 1, 1933. The west unit was designated in 1961. Both became a national park in 1994.

1950: “Short road” opens up Mount Lemmon

In 1928 and 1930 Pima County voters said “no” to replacing the long, circuitous route to Mount Lemmon through Oracle. Finally, with federal funds and prison laborers, including World War II conscientious objectors, the road was finished in 1950. Shortly thereafter, motorists by the thousands could enjoy 10 picnic areas, several campgrounds and Rose Canyon Lake at Tucson’s “Summer Paradise.”

1951: Hughes Aircraft comes to town

Metropolitan Tucson’s economy was boosted tremendously when the Hughes plant, now Raytheon, opened. Employing thousands of the area’s 140,000 residents, the company helped diversify the local economy, increase wages and attract other aerospace and technology companies.

1960: El Con Mall debuts

Expanding development, the automobile era and cheap land on the outskirts helped place downtown retailers in a precarious position by the mid-’50s. Their situation was exacerbated when El Con debuted with several large stores and plenty of free parking. The adjacent and iconic El Conquistador Hotel was demolished in 1968 to allow the mall to expand.

1965: Urban renewal begins

After earlier rejecting a much larger proposal, the Tucson City Council approved a 79-acre urban renewal project that controversially forced the relocation of hundreds of families and small businesses. The project, completed in the 1970s, included governmental buildings, the Tucson Convention Center and the La Placita retail complex. The project’s goal was to help revitalize downtown by attracting tourists and residents.

1966: The copper capital of the world

Mining’s role in Southern Arizona preceded the Gadsden Purchase. By the 1960s, an annual “Copper Days” celebration recognized the importance of the industry, which employed almost 9,000 people in Pima County at its peak in the 1970s. Today, the figure is approximately 2,300.

1974: Oro Valley incorporates

The move by Oro Valley’s 650 residents in 1970 was opposed by city and county officials. After a four-year legal battle, the community became the third municipality in Pima County with many residents hoping its population would not exceed 4,500. Today, more than 41,000 people call Oro Valley home.

1976/1977: Water rate hikes and a recall election

Seeking a sustainable rate structure, the Tucson City Council voted to dramatically raise water rates. In response, three council members were recalled while another resigned. Rates went up anyway, and lawns were soon being converted into the desert landscaping that today distinguishes the city from our neighbors to the north.

1984: Voters defeat Rillito-Pantano Parkway proposal

After political decisions cancelled earlier urban freeways, the Pima County Board of Supervisors sought voter approval for a north-side east-west parkway. Backed by many business and development industry leaders, the proposal was handily defeated at the polls. Thus, Tucson has no urban freeways besides I-10 and I-19.

1993-1999: Central Arizona Project water wars

Original plans for using CAP water in Tucson called for “direct delivery,” or sending the water to a west-side treatment plant, then delivering it to customers. Concerned about some chemicals to be added, supporters of recharging CAP water into the ground were partially successful at the ballot box. As a result, huge recharge basins were developed in Avra Valley and help to ensure sufficient water for Tucson even in drought conditions.

2010: Spring training baseball leaves town

Some of major league baseball’s greatest players thrilled locals as well as tourists during 64 years of spring training. That ended when the Arizona Diamondbacks and Colorado Rockies departed in 2010 for new stadiums in the Phoenix area. The Chicago White Sox left two years earlier. AAA teams moved on as well, leaving Tucson without professional baseball.