America's municipalities, as political actors, have become the cultural arena for changes in Black social integration and inclusion. Growing racial diversity presumably offers new opportunities for residential inclusion, resulting in less segregation, in an increasingly pluralistic and multiethnic society. This study examines patterns of Black segregation from Whites and non‐Blacks across America's increasingly multiracial municipalities over the last four decades. Our results reveal high, yet steep decline in Black segregation from Whites since 1990, as measured by the index of dissimilarity (D), decreasing from 77 to 64. However, Black–White segregation remains exceptionally high compared to other racial groups. Black segregation from Hispanics has also declined since 1990, but segregation from Asians has changed very little. In metro municipalities, fringe suburbs pose serious challenges for Black integration, suggesting new bastions of segregation. Nonmetro municipalities, particularly county seats, still show higher levels of segregation, reflecting enduring social structures that impede racial mixing. Fixed‐effects models that control for unobserved municipal‐period effects indicate that observed changes in the predictors cannot fully ‘explain’ the differentials in Black segregation or the large downward trend since 1990. Racial inequalities—in income, housing and labour market opportunities—nevertheless continue to reinforce persistent Black municipal segregation from Whites and other non‐Black populations. It remains to be seen whether Black segregation will continue to decline indefinitely in a multiethnic society or evolve in new and unexpected ways as racial diversity penetrates the American landscape.