In the 1913 case Pierce v. United States, the Supreme Court ruled on a matter involving fraudulent use of the U.S. mail system. The defendant, Pierce, was accused of using deceptive practices to sell land in Texas that he claimed was fertile and suitable for farming when it was not. He used brochures sent through mail to advertise these lands with false descriptions about their quality and value. The court held that his actions constituted fraud under federal law because they involved misrepresentations made with an intent to deceive potential buyers who relied on those representations in deciding whether or not to purchase land from him. The decision clarified what constitutes as fraud under federal laws governing misuse of mails: It is enough if one induces another's assent by means of material misstatements known by him/her to be untrue and intended by him/her to be acted upon by other party which does act upon them believing them true; thus causing injury/damage due such reliance.

In the dissenting opinion for Pierce v. United States, Justice Hughes argued that the defendants' convictions should be overturned due to a lack of evidence proving their intent to defraud. He believed that while they may have been guilty of making false statements, it was not clear whether these falsehoods were made with fraudulent intentions or simply as a result of negligence or mistake. Furthermore, he pointed out inconsistencies in how different courts had interpreted and applied the law regarding fraud, suggesting this ambiguity further complicated matters. Ultimately, he felt there was insufficient proof beyond reasonable doubt to uphold the convictions on charges of conspiracy to defraud and mail fraud.