Knowledge is quite limited about the extent and social correlates of marital fertility decline for the United States in the early part of the nineteenth century. Manuscripts from the New York State census of 1865 indicate a very slow decline in marital fertility during the initial decades of the nineteenth century and more rapid decline as the Civil War approached. Little evidence of fertility control within marriage is found for the very oldest women in the sample, but analysis of parity progression ratios indicates that some control had emerged by the midpoint of the nineteenth century. Fertility decline was most evident in the urban, more economically developed areas, but our data also indicate that the limited availability of agricultural land may have affected the transition. While a marital fertility transition occurred in nineteenth-century New York, many couples in various geographic areas and social strata continued to have quite high levels of fertility, indicating difficulties that were probably faced in controlling reproduction.