They replaced fitted leather cases that were supplied with the earliest cameras.
[1] In the 1970s, war and documentary photographers used fishing bags made by English companies Brady and Billingham.
[2] Billingham noticed their waterproof soft bags were popular with photographers and modified the fishing bag with padding to protect camera gear.
[3] In 1975, photojournalist Jim Domke wanted a bag to carry all his camera gear and worked with a tent manufacturer to prototype a canvas camera bag.
Feedback from photographers at the 1976 Republican National Convention changed the design to arrange the gear vertically, accessed from above.