The Texas Rangers have been called the oldest state-level law enforcement agency in the United States. The roots of that agency go back to 1823. The idea for the Texas Rangers started with Stephen Austin. He took over a contract his father had made to help settle the then Mexican province of Tejas. He was given authority to police the area.
In 1823, there were growing numbers of raids by Comanche and other Indian tribes. Austin formed a militia to protect the people from raids and from criminals. The militia men could join for days or months, depending on the need. Rather than paying his rangers with money, they received land for their services. Each ranger had to supply his own equipment (including horse, saddle, and weapons).
What kind of ability was looked for in a ranger? One of the most important was the ability to think for himself in a given situation and still be able to follow the rules. That same quality is still valued in rangers today.