The township of Willingboro enacted an ordinance that forbid the posting of For Sale signs or Sold signs on property because of a problem it had with 'panic selling' -- that is, selling by whites who feared that the township was becoming all black and that property values would decline. Linmark Associates (P), a New Jersey corporation, owned a piece of realty in the township. P brought this action against both the township and the building inspector charged with enforcing the ban on 'For Sale' signs, seeking declaratory and injunctive relief. The District Court granted a declaration of unconstitutionality, but a divided Court of Appeals reversed.