There were over 23 million non-citizens from many parts of the world who were living in the United States in 2016 according to data from the U.S. Census Bureau, and among them 11.3 million undocumented immigrants from many different countries. Legislative avenues have failed to regularize immigrants. This chapter describes a series of laws, policies, and changes in policy implementation that have targeted and often criminalized immigrants, and the resulting efforts to counter these policies and their effects throughout the United States.