Cemetery headstones provide an easily accessible source of demographic data in human populations. In common with other sources of demographic data, such as skeletal samples, cemetery data may not be representative of the populations from which they were derived. In some circumstances they can be reasonably representative, however, and in such cases they may provide signals about demographic changes in the population that contributed to the cemetery. We present here analyses of burials occurring between 1900 and 1990 at the Columbia Cemetery in Columbia, Missouri. Our analyses, in combination with archival materials relating to infrastructure improvements in Columbia and data on infectious disease mortality in the state of Missouri, show that patterns of death observed in the cemetery data provide evidence for the timing of changes in the health of Columbia's residents. At the time that major improvements in sanitation and hygiene were implemented, burials of individuals dying under age 45 decreased significantly while burials of individuals older than 45 remained relatively high. Furthermore, data on infectious disease mortality indicate significant declines in deaths from water- and milk-borne infections, but no change in mortality from respiratory illnesses. These data also indicate that observed changes occurred about a decade later in Columbia than in large cities and more densely populated states elsewhere in the United States. Thus, this study illustrates the value of cemetery data in helping to fill gaps about how and when different events known to affect patterns of birth and death may have played out across time and space.