Harlingen is a city in Cameron County in the heart of the Rio Grande Valley of south Texas, United States, about 30 miles (48 km) from the coast of the Gulf of Mexico. The city covers more than 34 square miles (88 km2), and is the second largest city in Cameron County and the sixth largest in the Rio Grande Valley. As of the 2010 Census the city had a total population of 64,849 and grew 12.5% since the 2000 Census.
Harlingen is a principal city of the Brownsville–Harlingen Metropolitan Statistical Area, which is part of the larger Brownsville-Harlingen-Raymondville combined statistical area.
Harlingen's strategic location at the intersection of U.S. highways 77 and 83 in northwestern Cameron County fostered its development as a distribution, shipping, and industrial center. In 1904 Lon C. Hill envisioned the Arroyo Colorado as a commercial waterway. He named the town he founded on the north bank after the Frisian city of Harlingen, Netherlands. The town's post office was established that year. The first school opened with fifteen pupils in 1905 near the Hill home, the first residence built in Harlingen. Harlingen incorporated on April 15, 1910, when the population totaled 1,126. In 1920 the census listed 1,748. The local economy at first was almost entirely agricultural. Major crops were vegetables and cotton.