The Dragones de Cuera or "presidial troops" according to their official name, constituted the Spanish cavalry established in the jails or forts, from where they protected the extensive North American border of the Spanish Empire. This special cavalry unit existed until 1821, when Spain lowered its flag in these territories.
They were created as such at the end of the 16th century, and since then they have been entrusted with the custody of the northern border of New Spain, which came to include Texas, Arizona, New Mexico, a large part of California and some areas of Colorado, Utah and Nevada. In addition to this task, they protected the communication routes between Mexico and California and between Texas and Florida.
Usually they were armed with fire guns, and swords, and the characteristic shield, used to defend themselves from the indian arrows.