A South African work that is in the public domain in South Africa according to this rule is in the public domain in the U.S. only if it was in the public domain in South Africa in 1996, e.g. if it was published before 1946 and no copyright was registered in the U.S. (This is the effect of 17 USC 104A with its critical date of January 1, 1996.)
Captions
Boer family with a wagon on a farm in South Africa circa 1900