How did the outbreak of the Civil War affect the Texas Rangers?

 More men were needed.  In Texas, state military leaders were concerned with protecting the frontier and trade.  To this end, they encouraged available men, including men considered too young, too old, or too disabled for Confederate service, to defend against specific Union attacks.  Other methods included using furloughed Confederate soldiers.

president thomas jefferson commissioned the expedition shortly after the louisiana purchase in 1803 to explore and to map the newly acquired territory, to find a practical route across the western half of the continent, and to establish an american presence in this territory before britain and other european powers