The Berkshire: a first class black pig with excellent lean meat . Occasionally, when commercial white pork becomes too bland and tasteless, some Berkshire genes are used to improve it.
The Tamworth: a red heritage breed producing the best bacon in the U.S., a direct descendant of the wild boars which roamed the forests of Staffordshire. Was introduced to North America around the 1870's. Very outdoorsy and athletic.
The Red Wattle: this one's really in danger of extinction, it has dark, lean tender meat. It originally came to New Orleans via New Caledonia and developed in Texas. He went out of fashion when people wanted pigs for lard.
The Duroc: Its genes appear in many modern breeds. One of the juiciest and tastiest.
The Gloucester Old Spot: a.k.a. The Iron Age Pig, this breed is a cross between the domestic and wild pig. Excellent meat, at one point there were great numbers in the U.S.
The Yorkshire: They originated in Yorkshire England, home of the famed All Creatures Great and Small stories. Yorkshires do very well on pasture and are excellent mothers weaning large numbers of piglets. They are a foundation breed crossed with other breeds to create modern commercial pig genetics.
The Large Black: A pasturing pig, small shoulders but very tasty lean hams. There are fewer than 200 in the U.S