Apparently pitting dogs against rats is a long time tradition here in New York. Recently we saw video of dogs killing rats in Washington Square Park—which PETA explained was "entirely illegal," even if the Parks Department didn't seem to know the rules. Well, back in the day there were no rules, and Ephemeral NY notes that New York after the civil war saw "a brutal pastime reached new heights in popularity: rat-baiting—pitting a terrier against a rat until they fought to the death."
The site takes a look at the famous rat-baiting dive known as Kit Burns’ Sportsmen’s Hall at 273 Water Street, of which Luc Sante once wrote: “The pits, at Kit Burns’ and elsewhere, were uscreened boxes, with zinc-lined wooden walls eight feet long and four and a half feet high. Matches typically drew no fewer than one hundred betting spectators, from all walks of life, with purses starting at $125. A good rat dog could kill a hundred rats in half an hour."
According to this site, the first account of rat-baiting appears in the January 29th, 1855 issue of the New York Tribune. Patrons of McLaughlin's pit were promised an evening of "bear-baiting, badger and coon drawing, wolf-hunting and rat-killing." Allegedly "the bear was baited by five dogs until he caught them in his paws and crunched them half to death, amid the yells and cheers of the assembled fancy... When the last matched dogs had been carried out dripping with blood, a bag of rats was emptied in the pit, and men and dogs jumped in, kicking up a general melee."
Just because these fights were going on all over town, doesn't mean they were supported by everyone, however. Edward Winslow Martin’s 1868 The Secrets of the Great City stated: “Most of our readers have witnessed a dog fight in the streets. Let them imagine the animals surrounded by a crowd of brutal wretches whose conduct stamps them as beneath the struggling beasts, and they will have a fair idea of the scene at Kit Burns.” Rat-baiting eventually ended (thanks to the ASPCA) around the same time the 19th Century came to a close.