How did access to electricity and modern household appliances affect families in the US? Guided by historical evidence that modern household technology saved time on housework and offered direct health benefits, I study the effects of electricity and modern appliances focusing specifically on the tradeoff between quantity and quality of children. The empirical analysis exploits large cross-county and cross-state variation in the timing of diffusion of electricity and modern appliances for the period 1930 to 1960. In the baseline models, I relate changes in the proportion of households with electricity or modern appliances to changes in fertility rates, school attendance, and infant mortality. The fact that the decision to purchase a modern appliance may have been correlated with unobservable family characteristics creates a challenging identification problem, which I address using a new dataset of the US power grid. This dataset provides information on the construction of over 1600 new power plants throughout the period. Identification relies on plausibly exogenous changes in the cost of supplying power to different communities based on their location. I find that modern household technologies led families to make a quantity-quality tradeoff in terms of children: modern appliances were associated with increases in early school attendance, decreases in infant mortality, and declines in fertility. The declines in infant mortality were particularly large in states that relied heavily on coal for heating and cooking, consistent with modern stoves directly reducing indoor air pollution. Meanwhile, health improvements were larger in states that had previously invested heavily in maternal education programs, suggesting that household modernization also led parents to provide better infant care. The results do not appear to have been driven by local economic development or changes in the quality of local health care. This analysis adds to our understanding of the causes of the dramatic health improvements throughout the first half of the 20th century, and provides insight into the benefits of investment in electricity infrastructure in developing countries.