Pre-Civil War black urbanization is examined using data from federal census records, 1790 to 1860. The black population is found to be as urban as the white population initially, but its urbanization underwent relative decline in the last two decades before the Civil War. Foreshadowing current patterns, the northern black population was heavily concentrated in the largest cities, and the free black population was the most urban of all groups. The timing of black urban decline in the North, as well as regional and size of place differences in that decline, suggest that both competition with immigrants in major eastern seaboard cities and the passage of the Fugitive Slave Law in 1850 contributed to black de-urbanization. For the South, the explanations of black urban decline proposed by Wade, Conrad and Meyer, Goldin, and Bonacich are evaluated, and Bonacich’s split labor market theory is judged to be most consistent with the demographic trends.