The City of Ladue, Missouri (the city) (plaintiff), enacted a zoning ordinance that prohibited non-family members from jointly occupying a home. The term “family” was defined as one or more individuals related by blood, marriage, or adoption. The purpose of the ordinance was to promote the health, safety, morals, and general welfare of the city. The city filed suit against Joan Horn and E. Terrence Jones (defendants), alleging that Horn and Jones violated the ordinance by cohabitating in a seven-bedroom house. The defendants had purchased the house together, and Horn’s two children resided along with Jones’s child in the house. Although the defendants were not legally married, Horn and Jones shared a common bedroom, maintained a joint checking account, ate meals together, and disciplined each other’s children. Horn and Jones filed a counterclaim against the city, alleging that the zoning ordinance was unconstitutional. The trial court entered a permanent injunction in favor of the city. Horn and Jones appealed. The enforcement of the injunction was stayed pending the appeal.