Jack was the pet and assistant of double leg amputee signalman James Wide, who worked for the Cape Town–Port Elizabeth Railway service. James "Jumper" Wide had been known for jumping between railcars until an accident where he fell and lost both of his legs. To assist in performing his duties, Wide purchased the baboon named Jack and trained him to push his wheelchair and to operate the railways signals under supervision.
After initial skepticism, the railway decided to officially employ Jack once his job competency was verified. The baboon was paid twenty cents a day, and half a bottle of beer each week. It is widely reported that in his nine years of employment with the railway company, Jack never made a single mistake.
- Cheney, Dorothy L.; Seyfarth, Robert M. (2008). The Primate Mind in Myth and Legend. University of Chicago Press. ISBN 0226102440.
- Conway Morris, Simon (2003). Life's Solution: Inevitable Humans in a Lonely Universe. Cambridge University Press. ISBN 9781139440806.
- Wallechinsky, David (1975). The People's Almanac. Doubleday. p. 697. ISBN 9780385040600.