Available as a pdf by request to jmheyman@utep.edu . Our central agenda is to rethink the concept of movement in anthropology and other social sciences. We do this through two themes-mobilities and enclosures-both of which draw our attention to power and its diverse outcomes, especially at borders. Enclosure addresses processes that delimit and restrict the movement of specific goods, people, and ideas, while mobilities concern processes that enable and induce such movements. Consideration of these themes breaks with theoretical tendencies that celebrate unbounded movement, and instead focuses us on the political-economic processes by which people, nature, commodities, and knowledge are bounded, emplaced, and allowed or forced to move. Mobilities and enclosures are plural, favoring close-grained ethnographic studies. They involve unequal rights and powers, demanding precision about the political implications of movements of various sorts. This introduction situates these themes in recent border studies and social theory more generally and summarizes how the authors in this special issue advance scholarship on these matters.