Since the early 19th century, opium was widely used as an ingredient in medicines, cough syrups, and child quieters. However, many 19th century doctors and opium experts, such as Dr. H.H. Kane and Dr. Leslie E. Keeley, made a distinction between opium used for smoking and that used for medicinal purposes, though they found no difference in addictive potential between them. As part of a larger campaign to rid the United States of Chinese influence, white American doctors claimed that opium smoking led to increased involvement in prostitution by young white women and to genetic contamination via miscegenation. Anti-Chinese advocates believed America faced a dual dilemma: opium smoking was ruining moral standards, and Chinese labor was lowering wages and taking jobs away from European-Americans.