After the war, he moved to New Mexico Territory, where he learned Spanish, studied law, and attained admission to the bar.

In addition to practicing law Catron was a member of the Santa Fe Ring of prominent attorneys, politicians and land speculators.

[8] During the American Civil War Catron joined the Confederate States Army, serving in Hiram M. Bledsoe's Battery, a unit of Sterling Price's command.

He traveled to New Mexico with two wagon loads of flour, which he sold to finance his legal studies, and a Spanish grammar book, which he used to begin to learn the language.

[13] In 1872 he was appointed United States Attorney for the District of New Mexico, an office previously held by his law partner, Civil War colleague and fellow Republican Stephen Benton Elkins, who had been elected to Congress.

As a member of the group of land speculators known as "Santa Fe Ring," he became by 1894[19] the largest landowner in the United States.

[20][21] After annexing New Mexico in 1848, the U.S. required that Spanish and Mexican land grants be "confirmed" by the U.S. courts and Congress.

The Santa Fe Ring of lawyers and politicians, often in league with the Surveyors General, abused the adjudication system for their own benefit.

Disputes about ownership have continued into the 21st century and erupted into violence on at least one occasion, a 1967 raid on the Rio Arriba County courthouse by Reies Tijerina and Hispanic claimants to grant land.

[30] At the start of his Senate career Catron served as Chairman of the Committee on Expenditures in the Interior Department.

[32] After leaving the Senate Catron returned to Santa Fe, where he resumed his law practice and business interests, and served in local offices including President of the Board of Education.

She had lived in Mankato, Minnesota, was a graduate of Oberlin College, and was teaching school when she met Catron.

They had five children, four of whom lived to adulthood: John Walz; Charles Christopher; Thomas Benton II; and Fletcher Arthur[39] Catron received an honorary Master of Arts degree from the University of Missouri in 1868, and in 1920 the University of Missouri awarded him an honorary LL.D.

[42] A Chicano Spanglish poem, Lo que dirá ("What He Will Say") was written by T. A. Tornillo and published in the October 15, 1892 edition of El Hispano Americano, a newspaper in Las Vegas, New Mexico.

It invites people not to vote for Catron in the November 8 election for Delegate to Congress and describes him as a ladrón banquero ("robber banker").