The ASPCA, the first humane society in North America and today one of the largest humane societies in the world, was founded by Henry Bergh and incorporated in 1866 by a special act of the New York State Legislature. (aspca.org)
HAHS was the first humane society established in the United States to focus specifically on large animals, primarily horses. (hahs.org)
Another place to start is the ASPCA, the first humane society to be established in North America and now one of the largest in the world. (onegreenplanet.org)