New York opened its first two municipal baths, floating pools moored at Manhattan piers, in the summer of 1870. Located near tenement districts where people lacked home baths, the municipal baths were immediately popular. By their second summer in operation, more than 860,000 bathers visited the city’s floating baths to wash and cool off. At the peak of the program, the Department of Public Works oversaw a fleet of nearly a dozen floating baths that hosted millions of visitors each summer.
Annual report of the Department of Public Works of the City of New York for the year ending April 10, 1872... (New York: Martin B. Brown, 1872), 36. Department of Public Works, Public Baths Under the Supervision of the President of the Borough [...] (New York: n.p., 1912).