[1] The United States portion was incorporated in 1900 as the Kansas City, Mexico, and Orient Railway.
The railroad was forced into bankruptcy in 1912, but its receiver, William T. Kemper, was to make a fortune when oil was discovered under its tracks.
[3] At the end of 1925, KCM&O and KCM&O of Texas (the portions of interstate railroads in Texas were required to be under unique charters) together operated 859 miles (1,382 km) of track over 738 miles (1,188 km) of right of way; they reported a total of 330 million net ton-miles of revenue freight and 8 million passenger-miles.
The KCM&O was acquired by the Atchison, Topeka and Santa Fe Railway in 1928, mainly to gain access to the West Texas oil fields.
Operating rights on the portion from San Angelo Junction (65 miles [105 km] NEE of San Angelo) to Presidio (known as South Orient Rail Line) later were awarded to Texas Pacifico Transportation.