General Taylor leads American troops into the disputed border area, across from the Mexican town of Matamoros

Under orders from President James Polk, General Zachary Taylor leads about 1,500 American troops into the disputed Texas-Mexico border area that lay between the Nueces and Rio Grande rivers. Taylor's men begin building Fort Texas (later Fort Brown) on the bank of the Rio Grande, across from the Mexican town of Matamoros. (By Matthew Pinsker)