Seaman was an attending surgeon at New York Hospital from 1796 until his death. He is best known for mapping the spread of yellow fever in New York City and introducing the smallpox vaccination to the United States.
Mapping of yellow fever
In 1795, yellow fever broke out in New York City. At the time, it was not known how yellow fever spread; some blamed incoming ships from the tropics. As the fever spread, Seaman mapped each case he could find in the New Slip area, marking which cases were fatal. He then mapped local waste sites, compared the two maps, and concluded that yellow fever originated in these waste areas. He wrote, in a 1796 account of the epidemic, that he was indebted to Benjamin Rush for "innovations in the treatment of the Epidemic Fever of Philadelphia of 1793." The city's Committee of Health asked for his advice regarding the disease's cause and prevention; Seaman recommended filling in areas that were below sea-level and wherever water tended to stagnate, cleaning and paving streets, covering sewers, and filling in the areas beneath granaries and docks. A fuller account and the maps he created were published in An Inquiry into the Cause of the Prevalence of the Yellow Fever in New-York in 1798.
Introduction of vaccination to the United States
His first child died of smallpox in 1795, a tragedy that spurred Seaman to identify preventative measures. At the time, vaccinations were not understood or trusted in the United States. Edward Jenner, a British physician, had just introduced vaccination in England. Seaman acquired the vaccination serum from Jenner and, in 1799, successfully vaccinated his own children with it. They were the first people to be vaccinated in the United States. Seaman later became friends with Jenner. Seaman went on to advocate for vaccination. In 1802, he coordinated a system to provide free vaccinations to the poor in New York City.
Education
Seaman taught medicine as well, focusing in particular on women's education. In 1798-9, Seaman founded the first instructional classes for nurses at New York Hospital, which continued until 1817. Seaman was the first American physician to teach a class of women in midwifery in the almshouse. He wrote The Midwives Monitor in 1800 for their instruction.
Legacy
Seaman, a Quaker, was against slavery and was a member of the New York Manumission Society, which advocated for the abolition of slavery in New York state. He died at the age of 47 from tuberculosis, leaving behind a legacy of public health innovations and advocacy. He had 10 children, including John Ferris Seaman and Valentine Seaman, who owned an estate in 1855 in the Inwood area of upper Manhattan. There, they constructed "Seaman's Folly," including a castle and a structure now known as the Seaman-Drake Arch. His papers are housed at the Samuel J. Wood Library at Weill Cornell Medicine.
