No known wild sheep are wool bearing. The supposed ancestors of the domestic sheep had long hair and a soft, downy undercoat, which under domestication gradually became wool, while the long hair disappeared. In this development, breeding, feed, climate, and protection were influential, as shown by an atavistic return of neglected sheep to long hair and rudimentary wool.
In the tombs and ruins of Egypt, Nineveh, and Babylon, in the barrows of early Britons, and among the relics of the Peruvians, fragments of woolen fabrics are found. The Romans as early as 200 B.C. began to improve their flocks, which became the progenitors of the famed Spanish Merino sheep. The Britons kept sheep and wove wool long before the Roman invasion, but the establishment by the Romans of a factory at Winchester probably improved their methods. William the Conqueror brought into England skilled Flemish weavers. Henry II encouraged wool industries by laws, cloth fairs, and guilds of weavers. Edward III brought weavers, dyers, and fullers from Flanders. England became the great wool-producing country of Europe, and wool was the staple of its industry until cotton began to overshadow it in the 18th cent.
In the American colonies, sheep raising started in Jamestown. Stringent English laws against exporting wool passed in an attempt to force the use of English cloth on the colonies, early drove the settlers to the raising of sheep. George Washington imported sheep and brought spinners and weavers from England. Early in the 19th cent., imported Merinos greatly improved the existing stock. Spinning and weaving were early established in New England, at first in homes, later in small factories. The first factory in America using water power to weave wool was established (1788) at Hartford, Conn., and was encouraged by tax exemption and a bounty on each yard woven.