Abstract: Like HIV in the twentieth century, yellow fever caused high mortality and fear in a global network of trade two-hundred years ago. Historians typically view yellow fever as a local, sporadic problem in the United States and Caribbean islands. This outlook distorts the significance of yellow fever for contemporaries. When yellow fever became pandemic in 1801, it launched a multi-national debate on health policy because a dense network of trade amplified risk of infection. The pandemic channeled medical research towards quarantine and drew Americans to the front lines of medical science. America’s rapid push into global markets underlay the prestige of American scholars. My dissertation spotlights the close link between maritime commerce and medical science when the United States first stood on the world stage as an independent trading power.