A teamster, in modern American English, is a truck driver. The trade union named after them is the International Brotherhood of Teamsters (IBT or Teamsters), one of the largest unions in the United States.
Originally, the term "teamster" referred to a person who drove a team of draft animals, usually a wagon drawn by oxen, horses, or mules. This term was common by the time of the Mexican-American War (1848) and the Indian Wars throughout the 19th and early 20th centuries on the American frontier.
A teamster might also drive pack animals, such as a muletrain, in which case he was also known as a muleteer or muleskinner. Another name for the occupation was bullwhacker, related to driving oxen. Today this person may be called an outfitter or packer. In Australian English, a teamster was also known as a bullocker or bullocky.
Further reading 
- Telleen, Maurice (1977), The Draft Horse Primer: A Guide to the Care and Use of Work Horses and Mules, Rodale Press, Emmaus, Pennsylvania, ISBN 0-87857-161-2
- Elser, Smoke (1980), Packin' in on Mules and Horses Mountain Press Publishing Co., Missoula, Montana, ISBN 0-87842-127-0
- Gebhards, Stacy V. (2000), When Mules Wear Diamonds: Mountain Packing with Mules and Horses Wilderness Skills, McCall, Idaho, OCLC 47630999
- Damerow, Gail; Ainsworth, Brandt and Edmunds, Bill (2001) Driving Draft Horses, DVD, Rural Heritage Video, Cedar Rapids, Iowa, ISBN 978-1-893707-31-3
- Damerow, Gail and Rice, Alina (2008), Draft Horses and Mules: Harnessing Equine Power for Farm & Show, Storey Publishing, North Adams, Massachusetts, ISBN 978-1-60342-081-5