The San Antonio and Aransas Pass Railway Company (S. A. & A. P.) was chartered by the State of Texas in 1884 to connect the city of San Antonio with Aransas Bay, and the rail line officially came to Hallettsville on April 23, 1887. A large celebration on that date brought 5,000 to town to witness the completion of the track over the Lavaca River around noon, and the evening arrival of the first train.
The S. A. & A. P. railway met financial ruin when a disastrous train wreck occurred on the wooden bridge over the Lavaca River on January 2, 1890. The river had risen to within fifteen feet of the bridge's rails because of heavy rains. The engineer crossed the river in order to reach the water tank at the other side, because the water was necessary to power the trains steam-driven engine. The engineer then crossed back over the bridge to reattach the remaining cars. Upon preparing to cross the bridge with the entire train, the engineer realized that the trestle had been washed away by the surging water. Although the engineer was able to stop the train at the edge of the river, the weight of the train's cargo caused it to plunge into the raging floodwaters below. The train carried liquor as part of its cargo, and the consumption of the liquor by spectators added to the confusion caused by the crowd of onlookers that soon appeared
at the site.
The wreck of the Don Milo, engine no. 54, caused additional problems for the S. A. & A. P., which had already been experiencing financial difficulties. The resulting lawsuits forced the company to reorganize, and the S. A. & A. P. was acquired by the Southern Pacific Transportation Company in 1892.