delivered the opinion of the Court.
The question in this case is whether a State’s unfair competition law can, consistently with the federal patent laws, impose liability for or prohibit the copying of an article which is protected by neither a federal patent nor a copyright. The respondent, Stiffel Company, secured design and mechanical patents on a “pole lamp” — a ver *226 tical tube having lamp fixtures along the outside, the tube being made so that it will stand upright between the floor and ceiling of a room. Pole lamps proved a decided commercial success, and soon after Stiffel brought them on the market Sears, Roebuck & Company put on the market a substantially identical lamp, which it sold more cheaply, Sears’ retail price being about the same as Stiffel’s wholesale price. Stiffel then brought this action against Sears in the United States District Court for the Northern District of Illinois, claiming in its first count that by copying its design Sears had infringed Stiffel’s patents and in its second count that by selling copies of Stiffel’s lamp Sears had caused confusion in the trade as to the source of the lamps and had thereby engaged in unfair competition under Illinois law. There was evidence that identifying tags were not attached to the Sears lamps although labels appeared on the cartons in which they were delivered to customers, that customers had asked Stiffel whether its lamps differed from Sears’, and that in two cases customers who had bought Stiffel lamps had complained to Stiffel on learning that Sears was selling substantially identical lamps at a much lower price.
The District Court, after holding the patents invalid for want of invention, went on to find as a fact that Sears’ lamp was “a substantially exact copy” of Stiffel’s and that the two lamps were so much alike, both in appearance and in functional details, “that confusion between them is likely, and some confusion has already occurred.” On these findings the court held Sears guilty of unfair competition, enjoined Sears “from unfairly competing with [Stiffel] by selling or attempting to sell pole lamps identical to or confusingly similar to” Stiffel’s lamp, and ordered an accounting to fix profits and damages resulting from Sears’ “unfair competition.”
*227
The Court of Appeals affirmed.
1
Before the Constitution was adopted, some States had granted patents either by special act or by general statute,
3
but when the Constitution was adopted provision for a federal patent law was made one of the enumerated powers of Congress because, as Madison put it in
The Federalist
No. 43, the States “cannot separately make effectual provision” for either patents or copyrights.
4
That constitutional provision is Art. I, § 8, cl. .8, which empowers Congress “To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries.” Pursuant to this constitu
*229
tional authority, Congress in 1790 enacted the first federal patent and copyright law, 1 Stat. 109, and ever since that time has fixed the conditions upon which patents and copyrights shall be granted, see 17 U. S. C. §§ 1-216; 35 U. S. C. §§ 1-293. These laws, like other laws of the United States enacted pursuant to constitutional authority, are the supreme law of the land. See
Sperry
v.
Florida,
The grant of a patent is the grant of a statutory monopoly;
5
indeed, the grant of patents in England was an explicit exception to the statute of James I prohibiting monopolies.
6
Patents are not given as favors, as was the case of monopolies given by the Tudor monarchs, see
The Case of Monopolies (Darcy
v.
Allein),
11 Co. Rep. 84 b., 77 Eng. Rep. 1260 (K. B. 1602), but are meant to encourage invention by rewarding the inventor with the right, limited to a term of years fixed by the patent, to exclude others from the use of his invention. During that' period of time no one may make, use, or sell the patented
*230
product without the patentee’s authority. 35 U. S. C. § 271. But in rewarding useful invention, the “rights and welfare of the community must be fairly dealt with and effectually guarded.”
Kendall
v.
Winsor,
Thus the patent system is one in which uniform federal standards are carefully used to promote invention *231 while at the same time preserving free competition. 7 Obviously a State could not, consistently with the Supremacy Clause of the Constitution, 8 extend the life of a patent beyond its expiration date or give a patent on an article which lacked the level of invention required for federal patents. To do either would run counter to the policy of Congress of granting patents only to true inventions, and then only for a limited time. Just as a State cannot encroach upon the federal patent laws directly, it cannot, under some other law, such as that forbidding unfair competition, give protection of a kind that clashes with the objectives of the federal patent laws.
In the present case the “pole lamp” sold by Stiffel has been held not to be entitled to the protection of either a mechanical or a design patent. An unpatentable article, like an article on which the patent has expired, is in the public domain and may be made and sold by whoever chooses to do so. What Sears did was to copy Stiffens design and to sell lamps almost identical to those sold by Stiffel. This it had every right to do under the federal patent laws. That Stiffel originated the pole lamp and made it popular is immaterial. “Sharing in the goodwill of an article unprotected by patent or trade-mark is the exercise of a right possessed by all — and in the free exercise of which the consuming public is deeply interested.”
Kellogg Co.
v.
National Biscuit Co., supra,
Sears has been held liable here for unfair competition because of a finding of likelihood of confusion based only on the fact .that Sears’ lamp was copied from Stiffel’s unpatented lamp and that consequently the two looked exactly alike. Of course there could be “confusion” as to who had manufactured these nearly identical articles. But mere inability of the public to tell two identical articles apart is not enough to support an injunction against copying or an award of damages for copying that which the federal patent laws permit to be copied. Doubtless a State may, in appropriate circumstances, require that goods, whether patented or unpatented, be labeled or that other precautionary steps be taken to prevent customers from being misled as to the source, just as it may protect businesses in the use of their trademarks, labels, or distinctive dress in the packaging of goods so as to prevent others, by imitating such markings, from misleading purchasers as to the source of the goods.
9
But because of the federal patent laws a State may not, when the article is unpatented and uncopyrighted, prohibit the
*233
copying of the article itself or award damages for such copying. Cf.
G. Ricordi & Co.
v.
Haendler,
Reversed.
[For concurring opinion of Mr. Justice Harlan, see post, p. 239.]
Notes
No review is sought here of the ruling affirming the District Court’s holding that the patent is invalid.
See I Walker, Patents (Deller ed. 1937), § 7.
The Federalist (Cooke ed. 1961) 288.
Patent rights exist only by virtue of statute.
Wheaton
v.
Peters,
The Statute of Monopolies, 21 Jac. I, c. 3 (1623), declared all monopolies “contrary to the Laws of this Realm” and “utterly void and of none Effect.” Section VI, however, excepted patents of 14 years to “the true and first Inventor and Inventors” of “new Manufactures” so long as they were “not contrary to the Law, nor mischievous to the State, by raising Prices of Commodities at home, or Hurt of Trade, or generally inconvenient . . . .” Much American patent law derives from English patent law. See
Pennock
v.
Dialogue,
The purpose of Congress to have national uniformity in patent and copyright laws can be inferred from such statutes as that which vests exclusive jurisdiction to hear patent and copyright cases in federal courts, 28 U. S. C. § 1338 (a), and that section of the Copyright Act which expressly saves state protection of unpublished writings but does not include published writings, 17 U. S. C. § 2.
U. S. Const., Art. VI.
It seems apparent that Illinois has not seen fit to impose liability on sellers who do not label their goods. Neither the discussions in the opinions below nor the briefs before us cite any Illinois statute or decision requiring labeling.
