I hope you enjoy this excerpt on western fashion from the Victorian/Old West section of the Historical Research Companion to Everything of Interest to a Romance Writer:
Belts? Another no. Not to hold up your pants anyway. The purpose of a belt was for securing pistols. In an article by G. Daniel Deweese for True West Magazine, he notes that belt loops were rare on pants until the 1920’s and goes on to say:
“Stetson is credited as the originator of the cowboy hat. Stetson was forced to move west from Philadelphia for his health. While residing in Colorado in the early 1860s, he conceived of the basic design for his western style hat which he later called “The Boss of the Plains.” In 1865, with his health improved, he returned to Philadelphia and began production of his western hat. The original “Boss of the Plains” had a four-inch brim and four-inch crown, was “natural-colored” and weighed two ounces. Around the base of the hat crown was a leather strap for a band. In the early 1870s, Stetson’s hats were produced in only one grade of felt (two ounces) and sold for five dollars.”
This is a Hold Up – on the belt’s purpose.