This plate, taken from the Horstmann catalog, depicts the new French inspired uniforms that were authorized by the regulations of 1851.
In theory, the Regulations of 1851 gave a neat picture of what a suitably uniformed, dashing Dragoon should look like: dark blue frock coat, “flower pot” shako, and gray-blue trousers. The nine-buttoned frock coat had orange collars and cuffs. For troopers of the First Dragoons, a brass number, “1”, was placed on the side of the collar. The first model (1851) shako bore a brass eagle and company letter, orange facing, and orange pompom. This uniform was prescribed by regulations for both dress and fatigue wear. The regulations called for the wearing of blass shoulder scales when “under arms.”
The long-tailed frock coat was heavy, and generally scorned by the troops because it impaired the Dragoon when he mounted or dismounted. The shako was stiff, hot, and hard to balance on one’s head while riding at a fast gait. The orange facings of the coat and shako faded rapidly beneath a bright southwestern sun and the cardboard-lined shako became misshaped after brief exposure to wet weather, thus, creating anything but a uniformed appearance to a line of troopers. Small wonder that the 1839 fatigue cap and jacket remained popular with the troops during the post Mexican War era.