单选题Questions 62 to 66 are based on the following passage. The era of the cowboy really began after the Civil War ( 1861-1865 ). During this decisive war the Texas cattle had roamed undisturbed in the wild, breeding freely on the plains and greatly increasing in number. By the end of the war, however, Texas was filled with wild cattle. The people in the mushrooming cities of the East and in the Middle West wanted more meat for their diet and local farmers could not keep up with their demands. Therefore, the need for the cowboy emerged from the demands of the people and the nature of the culture. An image of American folklore which has inspired songs, stories, folk tales and legends has been the cowboy. These romantic figures of the wild frontier probably can trace their origin back to the time of the Spanish conquistadors. The Spanish brought with them to the New World many young men who were experienced with cattle and horses. They were to evolve into the modern-day cowboy. These men were handy with tools and knew how to handle a horse. Some of them discovered the use of rope to catch cattle and developed the lariat. Their life was not an easy one. In winter they watched over the herds and in the springtime they selected cattle for market, often driving herds of them hundreds of miles to the nearest town. The cattle were then sold to buyers and the routine would start all over again. The life of a cowboy was an outdoor one endured under harsh conditions. His wide-brimmed hat protected him from the glaring summer sun and his heavy leather jacket and gloves were his defense against the cold winters. His workday was long beginning before sunrise and lasting well into the night. His best friend was his horse and he spent most of his waking hours in the saddle. His speech was a mixture of Spanish and English and at night by a campfire he wove his speech into songs about life on the prairie. A great boon to the life of the cowboy was the building of the railroads which connected eastern cities to those out West. In 1866 when the Kansas and Pacific railroad reached the small dusty village of Abilene in Kansas, the life of the cowboy was connected to the rest of the country. Hundreds of small cow towns grew up along the old trails which led the cattle to market, and thus the west became integrated into the economic life of the country. Today the life of the cowboy is quite different from those early days after the Civil War. Helicopters rather than horses are now used to round up the cattle and modem technology used in the ranches has made the cowboy's life less formidable. Yet, the legends which surround him continue to perpetuate his image as the mastertial hero of the Wild West.
单选题
The appearance of the cowboy in the United States was due to______.