In the Rosen v. United States case of 1895, Samuel Rosen was convicted for mailing obscene material in violation of federal law. The Supreme Court upheld his conviction by a vote of eight to one, arguing that the materials he mailed were indeed obscene and thus not protected under the First Amendment's freedom of speech clause. The court held that obscenity is not within the area of constitutionally protected speech or press because it has a tendency to deprave or corrupt its readers by inciting lascivious thoughts or desires. This decision established an important precedent regarding what constitutes obscenity and how it can be regulated by law.

In the dissenting opinion for Rosen v. United States, Justice Harlan argued that the majority's decision was a dangerous expansion of federal power over state jurisdiction. He contended that Congress did not have the authority to regulate obscene materials in individual states under its commerce powers because such regulation infringed upon states' rights to govern their own internal affairs. Furthermore, he believed this case set a precedent where Congress could potentially use its commerce powers to regulate any and all aspects of morality within individual states, which would undermine their sovereignty and violate principles of federalism enshrined in the Constitution. In his view, obscenity laws should be left entirely up to each state rather than being federally mandated or regulated.