In a comprehensive analysis of state and local sanctuary and anti-sanctuary policies, researchers have mapped the rapidly evolving legal immigration landscape in the US from 2000 to 2021. The dataset sheds light on trends in immigration legislation including ”punitive” preemption, state government tendencies to enact laws that are ideologically opposed to the current federal administration, and conservative states using preemption to control liberal localities. The findings of the study in the American Journal of Preventive Medicine, published by Elsevier, can be used to examine how changes in state and local immigration policies drive health outcomes among immigrants and their communities.