The Barred (or Plymouth) Rock originated in Massachusetts around 1869, and became popular very rapidly, due to its qualities as an outstanding farm chicken.The Plymouth Rock was a foundation breed for the broiler industry in the 1920's.
Barred Rock hens grow to 7 ½ pounds and roosters to 9 ½ pounds and their rate of lay is very good at around 250-300 brown eggs per year. They are calm and cold-hardy, and are early feathering. These chickens have a bright red single comb. Their plumage has feathers that are crossed by sharply defined, regular, parallel bars of alternate light and dark color. The barred color pattern is due to a dominant sex-linked gene. This gene prevents pigment on colored plumage, thus creating light bars on dark feathers. The male carries 2 copies of the gene and the female only carries one copy, which is why the males are usually lighter in color than the females.