County History
Willacy County Was Carved Out of Two Larger Counties in 1911
Willacy County was formed in 1911 from Cameron and Hidalgo counties and was reorganized in 1921 when much of its land became Kenedy County.
The Texas Legislature created Willacy County in 1911 and named it for state senator John G. Willacy. The county originally covered a large swath of South Texas ranch land. In 1921, most of that ranch territory was split off to form Kenedy County. What remained became the smaller Willacy County you see today.
Growth picked up after 1904 when the railroad reached the area. Milt White introduced Bermuda onions around 1912, and the crop became central to the local economy. Cotton and sorghum followed. The county seat, Raymondville, was established by Edward Burleson Raymond, who helped secure the railroad right-of-way. The Handbook of Texas at tshaonline.org has the full county history.
Source to confirm: Handbook of Texas — Willacy County