Thanks! I've found a source that indicates an early Houston-Galveston line in 1856 which didn't remain in operation long. The permenant line was initiated in 1860. I also found that during the Civil War, chemicals, particularly acids, were collected and used for the batteries from Sour Lake. There was supposed to be a line from Houston down to San Antonio. You would think there would have been one for the post on the Rio Grande?