White Croad Langshans are magnificent birds, they are an original breed in China.
Miss Croad quotes from a letter by G.P. Burnham, author of several books on poultry, to an American Poultry "Monthly" in 1879:
G.P.B. also makes mention of a letter received by him from the United States Consul Hang-kow, who describes this breed as among the best esteemed in China.
He says, "they are brought from the Langshan district;" he adds, "there is a clear white variety, as well as black, bred in the same district. They are very beautiful but scarce." 
In Australia white Croad Langshans appeared in about 2013. The first seem to have been the 'Bradshaw Whites' which may have been obtained by crossing black Langshans with Wyandottes. In Western Australia a cross with white Cochins appeared at about the same time.
In 2014, AvGen Poultry was successful in importing White Croad Langshans from the original stock in UK into Australia. Several Croad fanciers in NSW and Qld obtained stock from Avgen and set about creating a pool of the pure UK strain which has now increased significantly.
Crossing the UK strain with Australian stock has created birds of incredible size, beauty and vigour, and we have to very gratefully aknowledge the generosity of these first Australian breeders in making them available to other keepers.
White Croad Langshans carry the recessive white gene 'c' which also accounts for the plumage of the white varieties of Plymouth Rocks, Wyandottes, Sussex, Orpingtons, Silkies, Frizzles, Cochins, Pekins, Minorcas, Jersey Giants, Dorkings and Japanese bantams. The Recessive White gene changes all pigmented plumage of adult birds (phaeomelanin and eumelanin) to white, regardless of other mutations in the genotype.
From the above Punnett Squares it is obvious that once a white bird has been crossed into a black line any black offspring may be c/C, in other words carry the white gene. Only backcrossing to a white bird will show the hidden genes: A true black Croad Langshan will then produce only black offspring (C/C and C/c) and a "hybrid" black (C/c) will produce 50% black and 50% white chicks.
Very careful record keeping is essential.
In theory the quality of white could be further modified by several other genes like blue (Bl), Silver (S) Barring (B) and Mottling (Mo), but none of them is present in Croad Langshans. The Silver gene causes the green sheen of black Croad Langshans (who carry the recessive 'gold' (s) to turn blue which, according to some standards, is a severe fault.
White Croad Langshans appeared in US very early, either as what was thought of as "sports" (but was most likely a recombination of 2 recessive genes), or as direct imports.
Miss Croad wrote : In a letter we received from Mr. Kesling, the editor of the " California Cacklerl' he writes:
 A.C. Croad: The Langshan fowl; its history and characteristics with some comments on its early opponents (3rd edition), Bowers Brothers, London 1889. p.61
 A.C. Croad: The Langshan fowl; its history and characteristics with some comments on its early opponents (3rd edition), Bowers Brothers, London 1889. p.63