How do Muslim-Americans form beliefs about the treatment they expect to receive from US law enforcement? The results of an original, nationally-representative survey of Muslim- Americans suggest three key findings. First, Muslims’ awareness of group-based injustices increases across successive generations, with the most negative attitudes towards law enforcement held by U.S.-born Arabs and Blacks. The data also provides an empirical account of the effects of sending-country institutions on immigrants’ attitudes and experiences in their new host countries. Newer immigrants from countries with corrupt institutions bring with them to the United States more negative expectations of government than those who came from non-corrupt countries. By the time immigrants have naturalized, however, their attitudes no longer reflect the institutions of their sending-country. Immigrants who have gone through the naturalization process become more cynical, regardless of their country of origin. The findings reveal that while beliefs about government institutions are sticky, they are updated overtime with new experiences.