Harold Mayer was a renowned scholar of urban geography at the University of Wisconsin-Milwaukee. In addition to specializing in urban and transport geography of North America, focusing on New York, Chicago, Milwaukee, and British Columbia, Mayer travelled widely, taking photographs along the way. He used his extensive photographic collection to teach. For several years, he often returned to the same city to take pictures of the same site, to illustrate changes in the urban landscape. The American Geographical Society has his collection on display. He took these Kodachrome photographs of Manhattan, New York City, in the 1940s and 1950s.