The evolution of animal welfare law from the 1822 Martin Act to modern sentience legislation reflects changing moral understanding of animals, with significant gaps remaining in protection for billions of animals.
Animal welfare law represents the codification of evolving moral concern for animals. Progress has been real and significant — billions of animals are better protected today than a century ago. But gaps remain enormous: most farmed fish, invertebrates, and wild animals receive minimal legal protection. The direction of travel is toward expansion and strengthening, but the pace is inadequate given the scale of ongoing suffering.