Abstract
Nineteenth-century Mormon doctrine strongly emphasized high fertili ty, offering heavenly rewards to large families. This essay examines fertility in a Utah town, St. George, finding that there were no identifiable determinants of fertility other than Church doctrine. Polygamous fertility rates, contrary to ex pectations, were about the same as monogamous rates. Social standing likewise made no important difference in fertility, and the economic value of children as an incentive to high fertility is questionable in a town that had a labor surplus. The most likely cause of St. George's uniform pattern of natural fertility was the residents' desire to ensure their heavenly status.