The Gulf Coast Lines included the following railroads:
- New Orleans, Texas & Mexico – see history below
- Beaumont, Sour Lake & Western – Beaumont to HB&T connection Houston, 83 miles. Incorporated August 13, 1903 as the Beaumont, Sour Lake & Port Arthur Traction Co.; name changed to BSL&W June 30, 1904. Road opened June 19, 1907. BSL&W owns 25% of the Houston Belt & Terminal Ry.
- Orange & Northwestern – Orange to Newton TX, 61.5 miles. Chartered January 14, 1901 and opened January 1, 1902.
- New Iberia & Northern – Port Barre to New Iberia, LA, 63.6 miles. Incorporated April 2, 1907. Road built for StL&SF Ry and StL&SF notes were issued as payment thereof. Due to Frisco financial failure, the road was repossessed by the owners on May 1, 1914 and was subsequently purchased by the NOT&M Ry.
- Iberia, St Mary & Eastern – New Iberia to Patterson, LA, 48 miles. Operated under lease by New Iberia & Northern
- St. Louis, Brownsville & Mexico – Brownsville to Algoa TX, 343 mi plus assorted branches for total owned trackage of 504 miles. Incorporated January 5, 1903 and first segment opened July 4, 1904 from Brownsville-Robstown plus trackage rights over Texas-Mexican RR from Robstown to Corpus Christi. StLB&M owns 25% of the Houston Belt & Terminal Ry and is joint owner with National Railways of Mexico of the Brownsville & Matamoras Bridge Co. The bridge opened for traffic on July 31, 1910.
- Louisiana Southern – New Orleans to Bohemia, LA, 50 miles. Incorporated February 1, 1897; leased to the NOT&M February 1, 1911.
- International-Great Northern
- San Antonio Southern – Christine-Kirk, TX 39 mi plus trackage rights Kirk to San Antonio over I-GN. Incorporated January 1, 1920 for the purpose of acquiring the property of the Asphalt Belt RR.
- San Antonio Uvalde & Gulf – San Antonio to Crystal City, Pleasanton to Corpus Christi and branches, 317 mi. Incorporated April 17, 1912 as successor to the Crystal City & Uvalde RR
- Asphalt Belt
- San Benito & Rio Grande Valley – Fernando to Santa Maria TX and branches, 65 miles. Incorporated July 28, 1912. Road opened in 1912 and 1913.
- Sugar Land Ry – Cabell to Anchor, TX 39.28 miles.
- Asherton & Gulf – Asherton to Artesia Wells, TX, 32 miles. Incorporated in March 1908.
- Rio Grande City
- Houston & Brazos Valley – Purchased by NOT&M February 1, 1924. Incorporated April 3, 1907 as successor to Velasco, Brazos & Northern Ry
- Houston North Shore
New Orleans, Texas & Mexico (NOT&M)
The NOT&M served as the primary corporate structure under which the Gulf Coast Lines system was built, thus deserving a more detailed look at its organizational history.
The New Orleans, Texas & Mexico Railroad was originally chartered in Louisiana in May 1905, as the Colorado, Southern, New Orleans & Pacific RR. The CSNO&P name was changed to New Orleans, Texas & Mexico in April 1910. Trackage extended from Baton Rouge LA to Brownsville TX, and included subsidiaries Orange & Northwestern RR, Beaumont, Sour Lake & Western Ry, and St. Louis, Brownsville & Mexico Ry. These lines were originally owned by the Frisco, and were operated as the NOT&M Division of the St. Louis and San Francisco Railway. Trackage rights over the Yazoo & Mississippi Valley provided access between Baton Rouge and New Orleans.
The NOT&M went into receivership in July 1913. This receivership along with the Frisco’s financial distress wiped out all Frisco interest in NOT&M. A new corporation, the New Orleans, Texas & Mexico Railway, was incorporated in Louisiana on February 29, 1916, and took over operations on March 1, 1916. Operating under the name Gulf Coast Lines, the NOT&M, its subsidiaries and the Y&MV operating agreement formed a through line from New Orleans to Brownsville.
On June 2, 1924, Missouri Pacific purchased a sizable block of NOT&M capital stock, with an option to secure 51% of the stock to gain a contrilling interest. On June 21, 1924, NOT&M purchased sufficient stock of the International-Great Northern Railroad to gain control of that property. This purchase was on behalf of Missouri Pacific. The Gulf Coast Lines and I-GN were brought into the Missouri Pacific system in 1926.