In this study we have used data from the Icelandic census of 1901 to analyze the household position and occupation of widows aged 50 or more. Longitudinal data have been used to relate household position and migration to the time elapsed since entering widowhood. For most women in late-nineteenth-century Iceland, losing a husband resulted in the weakening of the economic support system. There were, however, considerable differences in the means of livelihood and household structures between urban and rural areas. A higher percentage of widows headed households in the towns and it was common for widows to leave rural areas and establish households in the towns. The growth of the towns created possibilities for women to support themselves by means not available to women in rural environments. The mean household size and the composition of widows' households in urban areas hardly changed at all with age. On the other hand, the mean household size of rural widows sharply declined with age, reflecting decreasing economic activity. We show that a similar proportion of widows in rural and urban areas lived in the households of married offspring. However, a higher percentage of widows heading households in the towns benefited financially from offspring living in separate households. The nature of the urban environment made it possible to create and maintain efficient support networks of neighbouring kin and friends.