Yick Wo v. Hopkins (1886)

Due to the various restrictions imposed on Chinese labor, particular areas of industry became concentrated with Chinese labor.  Chinese workers made up 97 percent of all persons working in cigar-making in the San Francisco area, 84 percent of the boot and shoemakers, 88 percent of the garment manufacturers and 89 percent of the laundry workers.

San Francisco subsequently passed a city ordinance prohibiting the operation of a laundry located in a wooden building without the consent of the Board of Supervisors.  Laundries in brick or stone buildings needed no comparable approval.  At first glance, the law seemed a reasonable exercise of the state's police power, because the wooden buildings were more vulnerable to fire, a problem that plagued San Francisco and other nineteenth-century cities.  However, at the time the ordinance was enacted, over 95 percent of the 320 laundries in the city were located in wooden buildings, and two-thirds of those had Chinese owners.

The Board of Supervisors granted permission to operate laundries in wooden buildings to none of the 200 Chinese applicants, including Yick Wo, who had operated a laundry in the city for many years before being refused a permit. When he continued to run the business, he was arrested and convicted for violating the ordinance.