The correct answer to this open question is the following.
Although there are no options attached we can say the following.
The group that most of the Americans living on the frontier supported was the Cowboys.
Yes, at the end of the 1800s in the frontier region, Cowboys made a name by themselves. Indeed, they became one of the symbols of the West, almost as the ideal heroic man of that time.
The very first cowboys started in México under the Spanish name of "vaqueros." They worked introducing cattle to the Mexican territory. Then, the American cowboy, not only whites but African Americans too. They worked for hours under harsh weather conditions, being hot conditions in summer and cold conditions in winter, and they really did not receive good salaries for the job they did.
