History of the Dorset Breed
It is said that centuries ago, Merino sheep were brought into Shoutwest England and were crossed with the Horned Sheep of Wales, which produced a desirable all-purpose sheep. Thus, the birth of the Horned Dorset sheep, the ancestors of the present day Dorset.
"The Breed For All Seasons"
Dorsets in America
Horned Dorsets were imported into this country in 1860 to the West Coast.  Horned Dorsets were the dominate type of Dorset sheep in America until the development of the Polled Dorsets in the 1950's.  Polled Dorsets were developed from a gene mutation.  The polled strain has helped Dorsets become one of the most popular sheep breeds in the country today, where it has the largest white face breed registry in the country and second overall.
History of Dorset Sheep