Harlingen (härˈlĭnjən) [key], city (1990 pop. 48,735), Cameron co., extreme S Tex.; inc. 1910. It is a shipping and processing center in the lower Rio Grande valley, an irrigated farming area yielding citrus and other fruits, grain, vegetables, sugar cane, and cotton. The city, which is linked to the Intracoastal Waterway by a barge channel, has food processing, apparel manufacturing, and factories making various chemical and metal products. Harlingen was founded (c.1904) with the coming of the railroad and grew with the agricultural development of the surrounding area. It is the seat of a boys' preparatory marine academy. An airfield located in Harlingen Industrial Air Park maintains flying models of U.S. World War II aircraft.