BALB/c is an albino, laboratory-bred strain of the House Mouse from which a number of common substrains are derived. Now over 200 generations from New York in 1920, BALB/c mice are distributed globally, and are among the most widely used inbred strains used in animal experimentation.
The founding animals of the strain were obtained by Halsey J. Bagg of Memorial Hospital, New York, from a mouse dealer in Ohio in 1913. From 1920, the progeny of the original colony were systematically inbred, sibling to sibling, for 26 generations over 15 years. During this time, the colony passed through the care of a number of scientists, including C.C. Little and E.C. MacDowell at the Carnegie Institution of Washington and H.J. Muller at the University of Texas. By 1935 the animals were in the possession of Muller's student, George Davis Snell, who moved them to The Jackson Laboratory. This stock provided the basis of all the BALB/c substrains that are now in use around the world.
Snell provided some animals from this stock to the National Institutes of Health (NIH) to maintain. In 1961 D. W. Bailey used some of these to generate a substrain at the University of California, San Francisco. In 1974, now 136 generations from the original breeding pair, these animals were returned to The Jackson Laboratory and were named BALB/cByJ. On 16 November 2005, The Jackson Laboratory reported this substrain had reached its 235th generation.