This article provides a comprehensive analysis of the circumstances surrounding the deaths of all deceased Presidents of the United States of America. Based on historical documents, medical conclusions, and expert assessments, the chronology and causes of death of the leaders of the United States are reconstructed. Particular attention is paid to eight presidents who died while in office, including four who fell at the hands of assassins and four who died of natural causes. The statistical analysis covers natural mortality, assassinations, diseases concealed from the public, and also unique historical coincidences related to the dates of the presidents' deaths.