linguistic:voice_change, structural:summarization
Later development of the coach

The coach had doors in the side, with an iron step protected by leather that became the "boot" in which servants might ride. The driver sat on a seat at the front, and the most important occupant sat in the back facing forwards. The earliest coaches can be seen at Veste Coburg, Lisbon, and the Moscow Kremlin, and they become a commonplace in European art. It was not until the 17th century that further innovations with steel springs and glazing took place, and only in the 18th century, with better road surfaces, was there a major innovation with the introduction of the steel C-spring.

Many innovations were proposed, and some patented, for new types of suspension or other features. It was only from the 18th century that changes to steering systems were suggested, including the use of the ' fifth wheel ' substituted for the pivoting fore-axle, and on which the carriage turned. Another proposal came from Erasmus Darwin, a young English doctor who was driving a carriage about 10,000 miles a year to visit patients all over England. Darwin found two essential problems or shortcomings of the commonly used light carriage or Hungarian carriage. First, the front wheels were turned by a pivoting front axle, which had been used for years, but these wheels were often quite small and hence the rider, carriage and horse felt the brunt of every bump on the road. Secondly, he recognized the danger of overturning.

A pivoting front axle changes a carriage's base from a rectangle to a triangle because the wheel on the inside of the turn is able to turn more sharply than the outside front wheel. Darwin suggested a fix for these insufficiencies by proposing a principle in which the two front wheels turn (independently of the front axle) about a centre that lies on the extended line of the back axle. This idea was later patented in 1818 as Ackermann steering. Darwin argued that carriages would then be easier to pull and less likely to overturn.

Carriage use in North America came with the establishment of European settlers. Early colonial horse tracks quickly grew into roads especially as the colonists extended their territories southwest. Colonists began using carts as these roads and trading increased between the north and south. Eventually, carriages or coaches were sought to transport goods as well as people. As in Europe, chariots, coaches and/or carriages were a mark of status. The tobacco planters of the South were some of the first Americans to use the carriage as a form of human transportation. As the tobacco farming industry grew in the southern colonies so did the frequency of carriages, coaches and wagons. Upon the turn of the 18th century, wheeled vehicle use in the colonies was at an all-time high. Carriages, coaches and wagons were being taxed based on the number of wheels they had. These taxes were implemented in the South primarily as the South had superior numbers of horses and wheeled vehicles when compared to the North. Europe, however, still used carriage transportation far more often and on a much larger scale than anywhere else in the world.