General Taylor Advances Army to the Rio Grande

On orders from President Polk, General Zachary Taylor marched his Army of Occupation from Corpus Christi south to the north bank of the Rio Grande, directly opposite the Mexican city of Matamoros. Taylor's men began construction of Fort Texas (later Fort Brown) in view of Mexican positions. Mexico viewed this advance into the disputed zone between the Nueces and Rio Grande as an act of invasion. War was now imminent.