The decision means many cultural icons, such as the film "The Wizard of Oz" and the earlier incarnations of Mickey Mouse, will remain outside the public domain, and U.S. copyright law will more closely fit European law.
Most copyrights will now be protected from the creation of the work until 70 years after the creator's death. Before a 1998 extension, copyright protection lasted for 50 years after a creator's death.
The Constitution says Congress can set copyrights for "limited times."
Speaking for the high court majority Wednesday, Justice Ruth Bader Ginsburg said, "Text (of the Constitution), history and precedent ... confirm that the copyright clause gives Congress wide leeway to prescribe 'limited times' for copyright protection ... "
The Constitution's copyright clause "speaks of 'times' that are 'limited,' not 'times' that are 'fixed' or 'inalterable,' " Ginsburg said.
Moreover, the Constitution gives Congress the power to extend copyrights for existing works as well as works that may be created in the future, she said.
Nor does the extension of copyrights inhibit free expression under the First Amendment, Ginsburg added. "Free speech in this area is not one-sided," she said. "On that point, this court has recognized, 'the Framers intended copyright itself to be (an) engine of free expression."
Stevens said the majority's opinion makes any action by Congress on copyrights and patents, "for all intents and purposes judicially unreviewable. That result cannot be squared with the basic tenets of our constitutional structure."
Breyer took a somewhat different tack. The law extending the copyright "falls outside the scope of legislative power that the copyright clause, read in light of the First Amendment, grants to Congress," he said.
The current case began in 1998, when Congress brought U.S. copyright law into conformity with the laws of the European Union.
The "copyright clause" of the Constitution gives Congress the "power 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."
Congress first used the power in 1790, when it enacted a number of copyright statutes.
Specifically, the Copyright Act of 1790 established a copyright term of 14 years for newly created works and the existing works protected by laws in the states.
Congress extended the protection in 1831 and again in 1909.
However, most copyright claims were protected by the Copyright Act of 1976, which gives an author the exclusive right to publish and reproduce an exclusive work during the author's life plus 50 years.
In 1998, Congress acted to make U.S. copyright law congruent with that of the EU. The Sonny Bono Copyright Term Extension Act, among other things, extends the term of copyright protection for 20 years.
"Thus, an additional term of 20 years is added to the duration of all existing copyrights," or for original works that at the time had not fallen into the public domain, the Justice Department told the Supreme Court in a brief.
A coalition of corporations, associations and individuals who use works in the public domain filed suit in Washington in January 1999, contending that Congress was exceeding its "copyright clause" power.
The Constitution says copyrights can be established only for "limited times," the group told the Supreme Court in a petition.
Because of the 1998 act, "works originally authored in 1923 that would have fallen into the public domain in 1998 could now remain under copyright until 2019 -- a term of 95 years," the groups petition said. For "an author who produced in the pattern of Irving Berlin (that) would mean a term of 140 years." Berlin, one of the most popular songwriters in U.S. history, died in 1989 at the age of 101.
When a federal judge and a federal appeals court ruled against them, the members of the coalition asked the Supreme Court for review.
A public group called the Internet Archive, a non-profit organization trying to build an Internet library, and a group of copyright law professors filed their own briefs asking the Supreme Court to hear the case.
The Supreme Court heard the case in October. Wednesday's ruling upholds the appeals court decision.
(No. 01-618, Eldred et al vs. Ashcroft.)