Called Chotilapacquen by Coahuiltecan-speaking groups, the river was named "Nueces" by Alonso de León referring to the abundant pecan tree groves. One of the first settlers to scout the area was Cpt. Blas María de la Garza Falcón in 1766. From before the end of the Texas Revolution, Mexico recognized that the Nueces River was historically the border between its state of Tejas and the rest of the country. However, the Republic of Texas claimed the Rio Grande as its border with Mexico, citing the Treaty of Velasco signed by Mexican President Santa Anna, who had agreed to the Rio Grande border after having lost the Battle of San Jacinto. This contention continued after the annexation of Texas by the United States, and was one of the causes of the Mexican–American War. The Treaty of Guadalupe Hidalgo ended the dispute, with Mexico—while under American occupation—recognizing the Rio Grande as its northern border.