The original bulldog was not only used for bullbating but was also used as an all-around working dog by small farmers and ranchers. Towards the end of World War II the American Bulldog almost went completely extinct in the United States and are only here today by the efforts of a returning war vet, John D. Johnson and another breeder, Alan Scott. Today American Bulldogs are used as "hog dogs", cattle drovers, and as working or sport canines.
http://en.wikipedia.org/wiki/American_Bulldog
http://www.dogbreedinfo.com/americanbulldog.htm
http://www.gopetsamerica.com/american-bulldog/american-bulldog.aspx