You are in the CarrTracks website Picture Gallery.
This gallery covers former Texas & Pacific trackage from near Longview, TX west to Midland and contains 41 pictures. The Texas & Pacific built from Longview to Dallas completing this line on July 1, 1873. The T&P became the second railroad to enter Dallas. The Houston and Texas Central had built through Dallas a year earlier on it way north to connect with the MKT.
In 1911 Dallas adopted the Kessler Plan which moved all railroads out of the central district and onto a belt line around the city. T&P trains going west swing southwest at T&P Junction (on the east side of Dallas, later named MP Junction) to Belt Junction, then swing northwest though the joint yard to Union Station. Union Station opened in 1916. If you have ever been to the Age of Steam Museum at Fair Park, it sits right next to the former T&P mainline that continued west, then down Pacific Avenue to just north of Union Station. Today's Central Expressway sits on top of the original Houston and Texas Central line through Dallas.
The Texas & Pacific Railroad had very few block signals before 1925. The railroad added 125 miles of signals in 1927 and 567 miles in 1928. The T&P came under the control of the Missouri Pacific in 1926 and was official merged with it in 1976.