After serving for a decade on the city council, including her 1969 service as the city's first womanmayor Pro Tem, Cockrell was elected in 1975 to the first of four two-year terms as Mayor of San Antonio. At the time of her inauguration, San Antonio's population gave her the status of the mayor over the largest American city being governed by a woman. She is often listed as the first woman in the United States to be elected mayor of a major metropolis. However, Bertha Knight Landes was mayor of Seattle 1926–1928. Cockrell's first three terms ran consecutively 1975–1981. At the end of her third term, she chose not to run because of the illness of her husband Sidney Earl Cockrell Jr. She was succeeded by Henry Cisneros. Widowed in 1986, she was elected to her fourth term as mayor in 1989 when Cisneros left office.
Retirement
After retiring from political office, Cockrell served on many municipal commissions and civic boards. In 2013, she retired as president of the San Antonio Parks Foundation, a position she had held since 1998. Cockrell was a member of the Hot Wells Conservancy Board, which is working with the Bexar CountyCommissioners Court to restore the former Hot Wells hotel, spa, and bathhouses, which flourished in the first two decades of the 20th century. It is located along the San Antonio River in the southside of the city. On May 29, 2019 Cockrell was denied to vote in the 2019 San Antonio mayoral election because she lacked the required identification under Texas ID laws. Many people in the San Antonio community as well as politicians such as Pete Buttigieg were outraged that Cockrell was denied to cast her ballot. The incident started up a controversy about Texas voter ID laws. On May 31, 2019, Cockrell casted her vote in the election.
Death
Cockrell's Health declined in the time leading up to her death. Cockrell died at the age of 97 under hospice care on August 29, 2019 in her apartment in San Antonio, Texas. On September 3, 2019, a public visitation was held at Mission Park Funeral Chapel North. On September 5, 2019, a private memorial service and a public tribute were held at the Lila Cockrell Theatre. Her final burial place is Mission Burial Park North in San Antonio.
Honors
The Lila Cockrell Theatre, named in her honor, is part of the Henry B. González Convention Center in Downtown San Antonio. Also, a meeting room at the Convention Center directly below the Theatre is named the Mayor Cockrell Room in her honor.