Below are the only APA recognised varieties of Leghorns. The term Heritage is debatable; however, the ALBC considers the mid 20th century as a cutoff point. So any variety that were in the SOP by 1950-60 would or could be considered Heritage. Now will new varieties be considered Heritage? Debatable. The Leghorn as a breed is Heritage. Every variety may not be. The RC Black and RC Buff were entered in 1981. Yet the SC Black was in the first SOP in 1874 and the SC Buff was added in 1894. So a Black and Buff Leghorn with SC would be Heritage and a RC Buff and Black would not by the ALBC definition.
As of June 1, 2010 the Mille Fleur Leghorns are not in the SOP. So that variety would not be Heritage by ALBC definition. Though it was most likely created by using Heritage varieties of Leghorns. Now where did I put those aspirins!
http://www.amerpoultryassn.com/APA_Recognized_Breeds_6_2010.pdf
Leghorn Rose Comb Black 1981 Mediterranean
Leghorn Rose Comb Buff 1981 Mediterranean
Leghorn Rose Comb Dark Brown 1883 Mediterranean
Leghorn Rose Comb Light Brown 1883 Mediterranean
Leghorn Rose Comb Silver 1981 Mediterranean
Leghorn Rose Comb White 1886 Mediterranean
Leghorn Single Comb Black 1874 Mediterranean
Leghorn Single Comb Black Tailed Red 1929 Mediterranean
Leghorn Single Comb Buff 1894 Mediterranean
Leghorn Single Comb Columbian 1929 Mediterranean
Leghorn Single Comb Dark Brown 1874 Mediterranean
Leghorn Single Comb Golden 1981 Mediterranean
Leghorn Single Comb Light Brown 1874 Mediterranean
Leghorn Single Comb Red 1929 Mediterranean
Leghorn Single Comb Silver 1894 Mediterranean
Leghorn Single Comb White 1874 Mediterranean
Missing the Exchequer variety. And a question: Where do the Danish Brown Leghorns fall in? Light Brown?