In 1897, about half of all American municipalities used lead pipes to distribute water. Employing data from Massachusetts, this paper compares infant death rates in cities that used lead water pipes to rates in cities that used nonlead pipes. In the average town in 1900, the use of lead pipes increased infant mortality by 25 to 50 percent. However, in cities using new pipes and distributing acidic water, lead pipes increased infant mortality three- to four-fold. Qualitative evidence supports the econometric results and indicates the adverse effects of lead extended beyond Massachusetts. (Contains 6 tables, 2 figures and 2 footnotes.)