Under Illinois law, any takeover offer for the shares of a target company must be registered with the Secretary of State. A target company was defined as a corporation or other issuer of securities of which shareholders of Illinois owned 10% of the class of equity securities subject to the offer or for which any of two of the three following conditions were met; the corporation had a principal executive office in the State, was organized under the laws of the State, or at least 10% of its stated capital or paid in surplus resided in the State. On January 19, 1979, MITE (P) initiated a cash tender offer for all shares of Chicago Rivet & Machine Co. a publicly held Illinois corporation. P filed a Schedule 14D-1 with the SEC in order to comply with the Williams Act. D did not comply with the Illinois Act. P then filed a declaratory relief action in that the Williams Act preempted State law. Rivet then responded three days later by indicating that the offer violated the Pennsylvania Takeover Disclosure Law. That action failed, and both Rivet and the Secretary of State of Illinois took steps to invoke the Illinois law. The District Court issued a preliminary injunction against the Secretary and issued a final judgment that the State law was preempted.