Excerpts from Books and Wikipedia
"Although early bills to regulate conditions had been defeated, in 1822, Richard Martin's Cattle Cruelty Bill was passed. The Reverend Arthur Broome then gathered supporters to enforce the Act by calling for prosecutions and issuing propaganda, and on June 17, 1824, this group, which included the slavery abolitionist William Wilberforce, formed the Society for the Prevention of Cruelty to Animals.… Anti-cruelty bills were passed in the United States in the 1830s, and in 1866, Henry Berg founded the American Society for the Prevention of Cruelty to Animals." [1001 Days]