A passenger railroad car or passenger car (American English), also called a passenger carriage, passenger coach (British English and International Union of Railways), or passenger bogie (Indian English) is a railroad car that is designed to carry passengers. The term passenger car can also be associated with a sleeping car, a baggage car, a dining car, railway post office and prisoner transport cars. The first passenger cars were built in the early 1800s with the advent of the first railroads, and were small and little more than converted freight cars. Early passenger cars were constructed from wood; in the 1900s construction shifted to steel and later aluminum for improved strength. Passenger cars have increased greatly in size from their earliest versions, with modern bi-level passenger cars capable of carrying over 100 passengers. Amenities for passengers have also improved over time, with developments such as lighting, heating, and air conditioning added for improved passenger comfort. In some countries, such as the UK, coaching stock that is designed, converted or adapted to not carry passengers, is referred to as "NPCS" (non-passenger coaching stock); similarly, in the US, some maintenance (engineering) stock can be known as "MOW" (maintenance of way). History 19th century: First passenger cars and early development Up until about the end of the 19th century, most passenger cars were constructed of wood. The first passenger trains did not travel very far, but they were able to haul many more passengers for a longer distance than wagons pulled by horses. As railways were first constructed in England, so too were the first passenger cars. One of the early coach designs was the "Stanhope". It featured a roof and small holes in the floor for drainage when it rained, and had separate compartments for different classes of travel. The only problem with this design is that the passengers were expected to stand for their entire trip. The first passenger cars in the United States resembled stagecoaches. They were short, often less than long and had two axles. British railways had a head start on American railroads, with the first "bed-carriage" (an early sleeping car) being built there as early as 1838 for use on the London and Birmingham Railway and the Grand Junction Railway. Britain's early sleepers, when made up for sleeping, extended the foot of the bed into a boot section at the end of the carriage. The cars were still