In the 18th and 19th centuries, in the vast land of the western United States, there were a group of enthusiastic and fearless pioneers—cowboys, also known as heroes on horseback. They are the explorers in the development of the West. In the long and arduous process, cowboys must be able to withstand hardships, and have to deal with various accidents and dangers. So the quality of sharpness, courage, and calmness is essential for cowboys.