Chester White is a breed of pig originated in Chester County, Pennsylvania and thereby derived its breed name. At first it was called the Chester County White, but later the "county" was dropped.
Previous to 1812 there were Yorkshire and Lincolnshire animals that had come from England. The Chester breed was derived in Jefferson County, New York. These three breeds were intermingled for some years previous to 1815. Sometime between 1815 and 1818, Capt. James Jeffries imported from England one white boar which was referred to as a Bedforshire or Cumberland. This boar was used extensively on white animals in this county and from these matings the Chester White breed started.