Supreme Court case Euclid v. Ambler ruled that zoning is constitutional, finding that use districts are within a state’s power to protect the public welfare. The case also upheld a municipality’s ability to regulate the location multi-family construction, saying “very often the apartment house is a mere parasite, constructed in order to take advantage of open spaces and attractive surroundings created by the residential character of the district” and that said apartment houses “come very near to being nuisances” when they are in single-family districts.