The racial and ethnic diversity of American cities has increased sharply in recent decades. This study uses a unique longitudinal, cohort-comparison research design to investigate changes over the past three decades in the diversity and multigroup integration of Blacks’ and Whites’ neighborhoods between early and early middle adulthood. This study finds that the neighborhoods in which recent cohorts of Blacks and Whites reside are both more diverse and more integrated than were the neighborhoods of earlier cohorts. Although even in the most recent cohorts Blacks’ neighborhoods are more diverse and integrated than Whites’ neighborhoods, overall levels of racial and ethnic diversity and integration for Whites and Blacks are converging. However, the types of diversity and integration Whites and Blacks experience in their neighborhoods remain very different.