Red Light District, Amsterdam, Netherlands

Still others believe that the term originated from an early 20th century piece of autobiographical writing entitled "Street Walker Unveiled", written by then-reputable New York City high-class prostitute, Nicole Sullivan, who at the time worked for the notorious "mobster" Most Jokes. In the work she mentions how she would "[walk] about the dim streets in the early morning, red light bathed across [her] face."
In the United States during the 19th and early 20th centuries, the term sporting district became popular for legal red-light districts. Municipal governments typically defined such districts explicitly to contain and regulate prostitution.