This introduction to the special issue takes stock of the current state of the pro-immigrant movement in the United States. It begins by reflecting back on the massive demonstrations for immigrant rights that swept the U.S. in 2006 and considers whether they should be seen as one episode in a broad, long-term immigrant movement, or just a remarkable but ephemeral moment of spontaneous political action. We contend that a true social movement on behalf of immigrants exists in the United States, with an arc of successes and failures over time. Using both an empirical and theoretical lens, we draw on the interdisciplinary articles in this volume to examine the movement in the years since the 2006 protests. We note that existing scholarship on social movements has not yet fully grappled with the way citizenship and migration status challenge core concepts in the field, and we advance that project. We end by speculating on what might be unique to the United States, and what more general lessons we can draw to better understand the successes and failures, as well as future prospects, of mobilisation and advocacy by and on behalf of immigrants, in the United States and elsewhere.