Alamo located in the Rio Grande Valley in what is nicknamed the "Land of Two Summers", is a city in the irrigated area of southern Hidalgo County, Texas, United States. Known as the "Refuge to the Valley", it is located in an area of abundant vegetable farming and citrus groves, and is a noted winter resort/retirement town near the Mexico–U.S. border. Alamo is one of the Rio Grande Valley's gateways to Mexico, via U.S. Route 281 and Nuevo Progreso, Tamaulipas, as well as a gateway to the Santa Ana National Wildlife Refuge. Alamo's population was 18,353 at the 2010 census and an estimated 19,910 in 2019.
Alamo is part of the McAllen–Edinburg–Mission and Reynosa–McAllen metropolitan areas. As of the census of 2000, 14,760 people, 4,621 households, and 3,826 families resided in the city. The population density was 2,580.8 people per square mile (996.3/km2). The 6,208 housing units averaged 1,085.5 per square mile (419.0/km2). The racial makeup of the city was 83.61% White (including Hispanics or Latinos), 0.21% African American, 0.43% Native American, 0.09% Asian, 13.73% from other races, and 1.94% from two or more races. Hispanics or Latinos people of any race were 78.10% of the population.
Of the 4,621 households, 36.5% had children under the age of 18 living with them, 66.2% were married couples living together, 13.3% had a female householder with no husband present, and 17.2% were not families. About 15.1% of all households were made up of individuals, and 10.2% had someone living alone who was 65 years of age or older. The average household size was 3.19 and the average family size was 3.57.