The Pony Express was a North American postal service in operation from 1860-1861. Although short-lived, the service highlighted the need for fast communication between the booming West Coast and the more settled and industrial East. In those days, the fastest means of transcontinental transportation was by horse, thus the Pony Express needed animals that could withstand the difficult terrain and provide speed and endurance.
Stations for the mail system were placed about 10 miles (16 km) apart, considered to be the maximum distance a horse could gallop. The animals used were chosen for their hardiness and speed, qualities natural to certain breeds. The term Pony Express is actually, a misnomer, for while the animals were generally small and compact, they were, in fact, horses.
During the 1800s, America had several varieties of work horses available to them that proved useful in the mail operation. Mustangs, wild horses descended from the mounts of Spanish conquistadors, were prized for their compact frame and hardy disposition. Morgan horses were one of the first truly American breeds, known for versatility and strength. These breeds, along with pintos and thoroughbreds, were the animals of choice for the Pony Express.
The confusion over whether the storied mail-horses were ponies may come from the short stature of the animals used by the company. Mustangs and Morgans are extremely muscular breeds, but rarely reach over 15 hands (5 ft or about 1.5 m). The 400 horses purchased by the company averaged 14.2 hands (about 4.8 ft or 1.47 m) and most weighed around 900 lbs (408 kg). Typically, a pony is considered any member of the equus caballus that measures under 14.1 hands (about 4.75 ft or 1.45 m), thus making most of the animals too large to be true ponies.
The Pony Express was an extremely useful organization, able to cut down the transit time for mail considerably. At top speed, the mail route could cross the country in 10 days. Until that time, the transit typically took anywhere from one month to six months, depending on the routes and means of transportation used. Unfortunately, the service was quickly supplanted with the newly invented telegraph. Although the service lasted less than two years, the Pony Express became a romanticized symbol of the Old West, and many statues and American museums honor the memory and ingenuity of the inventors and their hardy work horses.