Cattle drives were a major economic activity in the 19th and early 20th century American West, particularly between 1850s and 1910s. In this period, 27 million cattle were driven from Texas to railheads in Kansas, for shipment to stockyards in Louisiana and points east. The long distances covered, the need for periodic rests by riders and animals, and the establishment of railheads led to the development of "cow towns" across the frontier. Due to the extensive treatment of cattle drives in fiction and film, the horse has become the worldwide iconic image of the American West, where cattle drives still occur. Movement of cattle Cattle drives represented a compromise between the desire to get cattle to market as quickly as possible and the need to maintain the animals at a marketable weight. While cattle could be driven as far as in a single day, they would lose so much weight that they would be hard to sell when they reached the end of the trail. Usually they were taken shorter distances each day, allowed periods to rest and graze both at midday and at night. On average, a herd could maintain a healthy weight moving about per day. Such a pace meant that it would take as long as two months to travel from a home ranch to a railhead. The Chisholm Trail, for example, was long. On average, a single herd of cattle on a long drive (for example, Texas to Kansas railheads) numbered about 3,000 head. To herd the cattle, a crew of at least 10 cowboys was needed, with three horses per cowboy. Cowboys worked in shifts to watch the cattle 24 hours a day, herding them in the proper direction in the daytime and watching them at night to prevent stampedes and deter theft. The crew also included a cook, who drove a chuck wagon, usually pulled by oxen, and a horse wrangler to take charge of the remuda (spare horses). The wrangler on a cattle drive was often a very young cowboy or one of lower social status, but the cook was a particularly well-respected member of the crew, as not only was he in charge of the food, he also was in charge of medical supplies and had a working knowledge of practical medicine. Origins Long-distance cattle driving was traditional in Mexico, California, and Texas, and horse herds were sometimes similarly driven. The Spaniards