The paper utilizes a natural experiment approach to estimate the impact of exogenous social and political events on suicide behavior in the United States between 1910 and 1920. The study is concerned with determining the impact of World War I, the great Influenza Epidemic, and the prohibition experiment on suicide. Estimating the monthly population in the United States registration area from 1910 to 1920, monthly suicide and mortality rates are computed. A time-series model is postulated, and second-order autoregressive estimates are used to determine the impact of the independent variables in the model. It is concluded that World War I did not influence suicide; the Great Influenza Epidemic caused it to increase; and the continuing decline in alcohol consumption between 1910 and 1920 depressed national suicide rates. Further individual-level aggregate studies are needed to confirm the findings of the study.