We find that fertility varies by immigrant generation, with significant declines between the first and subsequent generations for groups with large immigrant population. However, we find that personal characteristics--such as educational attainment, marital status, and income levels--are much more important than immigrant generation in understanding fertility outcomes. In fact, generations are not independently important once these personal characteristics are controlled for. We maintain that declining fertility levels among the descendants of Mexican and Central American immigrants are primarily the result of higher educational attainment levels, lower rates of marriage, and lower poverty. For example, a four-year increase in educational attainment decreases children ever born (CEB) by half a child. We conclude that immigrant generation serves as a proxy for changes in other personal characteristics that decrease fertility. Neighborhood characteristics have some bearing on fertility, but the correlations are relatively weak. Among Mexican and Central American immigrants and their descendants, the most consistent predictor of children ever born (CEB) at the neighborhood level is the percentage of Hispanic adults. However, no neighborhood characteristics bear any statistical relationship to current fertility, the measure that emphasizes recent births. This pattern of evidence suggests that the observed relationships between neighborhood characteristics and fertility are based on selection into the neighborhood rather than on neighborhood influences as such.