Attitudes toward fresh air and fear of stenches guided choices that restructured and changed the urban environment and governance between 1840 and 1880. This study of olfactory-inspired reforms demonstrates the cultural significance of nuisance beyond the courtroom. City dwellers used their understanding of stench nuisance as detrimental to health to construct smellscapes or olfactory maps of New York City. Such maps identified health threats and guided movements through or out of the city. These maps proliferated before and after the creation of the Metropolitan Board of Health in 1866. Sanitarian concern about stenches echoed lay concerns, and encouraged the creation of standing health boards. These boards mapped air currents that crossed political boundaries rather than pursuing individuals’ stench complaints. Considering individuals’ smellscapes alongside the health board’s maps demonstrates that 1866 was a turning point for the creation of both institutionalized public health and the conflict between lay and expert.