Under one theory, offered by Terry Kogan, sex-separation as a standard did not emerge in the U.S. until the late nineteenth century. The theory is that the development was a reflection of women's shift and growth in society, i.e. after women entered the workforce and factories. Massachusetts might have been the first state to pass a law mandating sex-separation in 1887. It was titled "An Act To Secure Proper Sanitary Provisions in Factories and Workshops." The law required establishments to have separate toilets in businesses. The act called for suitable and separate toilets for females in the workplace.