Mission is located at 26°12′41″N 98°19′17″W (26.211402, -98.321277).
According to the United States Census Bureau, the city has a total area of 24.1 square miles (62 km2), of which, 24.1 square miles (62 km2) of it is land and 0.04% is water.
As of the census of 2000, there were 45,408 people, 13,766 households, and 11,384 families residing in the city. The population density was 1,881.9 people per square mile (726.6/km²). There were 17,723 housing units at an average density of 734.5 per square mile (283.6/km²). The racial makeup of the city was 77.63% White, 0.37% African American, 0.38% Native American, 1.63% Asian, 0.01% Pacific Islander, 18.64% from other races, and 2.34% from two or more races. Hispanic or Latino of any race were 81.03% of the population.
There were 13,766 households out of which 43.4% had children under the age of 18 living with them, 64.8% were married couples living together, 14.5% had a female householder with no husband present, and 17.3% were non-families. 15.3% of all households were made up of individuals and 9.1% had someone living alone who was 65 years of age or older. The average household size was 3.29 and the average family size was 3.68.
In the city, the population was spread out with 32.1% under the age of 18, 9.8% from 18 to 24, 26.8% from 25 to 44, 17.1% from 45 to 64, and 14.2% who were 65 years of age or older. The median age was 30 years. For every 100 females there were 91.1 males. For every 100 females age 18 and over, there were 85.3 males.
The median income for a household in the city was $30,647, and the median income for a family was $33,465. Males had a median income of $25,710 versus $20,718 for females. The per capita income for the city was $12,796. About 22.6% of families and 26.8% of the population were below the poverty line, including 37.4% of those under age 18 and 15.6% of those age 65 or over.
The United States Postal Service operates in the city of Mission. Local zip codes include 78571, 78572, 78573, and 78574.
Mission shares the same economic growth that nearby McAllen enjoys. The Mission Economic Development Authority promotes development in the area. The city has been advertised as the "Home of the Ruby Red Grapefruit" since 1921, due to the fruit being commonly grown in the area.; the city is also home to the Texas Citrus Exchange. The city holds an annual parade along Conway Avenue called the Texas Citrus Fiesta Parade, which features fruit-decorated floats, bands, law enforcement agencies, and fire departments, and many local and city government officials. Moore Air Force Base (deactivated) is located 14 miles northwest of the city. It is the location of the First Lift Station of the Mission Canal Company that once irrigated 15,000 acres (61 km2) of farmland in the Rio Grande Valley.Fortunato Benavides, Judge on the U.S. Court of Appeals for the Fifth Circuit, born in Mission
Lloyd Bentsen, former U.S. Senator and vice-presidential nominee, born in Mission in 1921
William Jennings Bryan, presidential candidate and former Secretary of State, lived for a time in Mission
William S. Burroughs, writer of Naked Lunch, lived in Mission for a short while and wrote about it in Junkie
Jorge Cantu, MLB player from Sharyland High School, who played for Tampa Bay Rays, Cincinnati Reds, Florida Marlins, Texas Rangers, San Diego Padres, and now playing for Colorado Rockies
Koy Detmer, brother of Heisman Trophy winner Ty Detmer, played for and carried the Mission Eagles football team to the Semi-finals in Texas 5A football under the leadership of his father, Sonny Detmer
Jaime Garcia, professional MLB player from Sharyland High School playing with 2011 World Series Champions, St. Louis Cardinals
Kika de la Garza, former U.S. representative
Lena Guerrero, the first woman and first ethnic minority person to serve on the regulatory Texas Railroad Commission
Joe M. Kilgore, former U.S. representative, reared partly in Mission.
Tom Landry, Hall of Fame coach of the Dallas Cowboys, born and raised, played for Mission High School
Tito Santana (aka Merced Solis), former World Wrestling Federation (now WWE) star
Trinidad Silva, actor
Jamaar Taylor, attended Mission High School and played football, later being drafted by the New York Giants. Then after his retirement he helped coach at Mission Veterans Memorial High School for a brief period.
Most of Mission is a part of the Mission Consolidated Independent School District. Other portions extend into the La Joya Independent School District and the Sharyland Independent School District. In addition, South Texas Independent School District operates magnet schools that serve the community.
Mission is also the site of San Juan Diego Academy, a Catholic high school operated by the Catholic Diocese of Brownsville.
The Speer Memorial Library serves Mission. The facility has 48,760 square feet (4,530 m2) of space.
The library originated in March 1914, when the Civic League of Mission was formed to maintain a park and form a library. The first library board included officers from the civic league. In 1929 the City of Mission passed an ordinance making the library a part of the city government. In 1930 the library was in a room in the First National Bank. At a later time it moved to the Mission City Hall. From the early 1930s until 1947 the city library shared facilities with the school library. By 1960 it outgrew the building it had occupied. In 1976 Juanita Speer Farley donated the deed to her property to the city. A new library, designed by Warren Suter, an architect from Mission, was constructed in 1976 and 1977. The official completion date of the 14,000 square feet (1,300 m2) library was June 1, 1977. An addition in 1988 increased the library's square footage to 18,660 square feet (1,734 m2). An additional expansion of 30,100 square feet (2,800 m2), designed by architect TAG International, L.L.P. and constructed by Velasco Construction, was scheduled to be completed in March 2005, and the renovation of the older portions of the library was scheduled to begin afterwards.KCAS The New KCAS 91.5 FM - Renewing the Mind Official Site