Pit Bull

From : Wikipedia
Pit Bull is a term commonly used to describe several types of dogs with similar physical characteristics. Its use in media is often vague and rarely descriptive of specific breeds. There are several physically similar breeds that are often termed "pit bull" in English speaking countries, including the American Pit Bull Terrier, American Staffordshire Terrier, Staffordshire Bull Terrier, Perro de Presa Canario, Cane Corso, Dogo Argentino, Alano Espanol, Japanese Tosa, Dogue de Bordeaux, and Perro de Pelea. These breeds are usually not included by name in any Breed-Specific Legislation (see below), but are sometimes included because of a broad definition and confusion as to what a pit bull actually is. All of these breeds as well as many others (including Great Danes, Newfoundlands and Rottweilers) are members of the Molosser family of dog breeds

The ancestors of modern pit bulls come from the bulldogs and terriers of England. At one time, every county in England had its own breed of terrier. Many of these still exist; however, some have evolved into new ones. Such is the case for the English White and the Black and Tan terriers, whose descendants include the bull-and-terriers, the Fox Terrier, and the Manchester Terrier. Terriers served an important purpose in England by killing vermin that might otherwise ruin crops, damage property, or spread disease such as the Black Plague. The development of sports such as rat- or badger-baiting further added to the breeds' importance.
Mastiff type dogs also have a long history in England; they are thought to have been brought by the Celts. It is also known that the Normans introduced the Alaunt. These dogs were used in battle and for guarding, but they also served utilitarian purposes, such as farm work. Specifically, these dogs accompanied farmers into the fields to assist with bringing bulls in for breeding, castration, or slaughter. The dogs, known generally as bulldogs, protected the farmer by subduing the bull if it attempted to gore him. Typically a dog would do this by biting the bull on the nose and holding on until the bull submitted. Bulldogs were bred to have powerful, muscular bodies and the resolve to hold onto a violently struggling bull despite injury. These traits permitted the development and rise of the bloody sports of bull-baiting and bear-baiting. In Elizabethan England, these spectacles were popular forms of entertainment. However, in 1835, bull-baiting and bear-baiting were abolished by Parliament as cruel, and the custom died out over the following years.

Dog fights
Pit bulls are often used for dog fights, due to their strength, courage and widespread availability. Fight training often means using other dogs (especially females) as 'bait dogs' which have their muzzles taped shut while the fighting dog attacks them as a form of training for the pit. Although dog fighting is illegal in the United States, it is still practiced, and is sometimes accompanied by gambling.