Mr. Justice Pitney

delivered the opinion of the court.

This is a review, under Rev. Stat., § 709, of a judgment *606 recovered against the plaintiff in error for damages on account of the déath of one Charles Albert Schuyler, occasioned by the derailment of a mail train at Gertney, Utah, January 14, 1907, while the deceased was riding thereon. It appears that he was an assistant chief clerk in the United States Railway Mail Service, and held a commission or certificate signed by the Postmaster General in the following form:

“Postoffice Department, Washington, D. C.

“To Whom Concerned:

“The bearer hereof, Charles Albert Schuyler, has been appointed an assistant chief clerk railway mail service with headquarters Ogden, Utah, and will be obeyed and respected accordingly. Railroad companies are requested to extend to the holder of this commission the facilities of free transportation on the lines named on opposite page... If fare is charged receipt should be given. Valid only when issued through the office of the second assistant postmaster general and countersigned by James E. White.

‘G. B. CORTELYOU.

“Countersigned:

“JAMES E. WHITE,

“ General Superintendent.”

■On opposite page:

“Good, between all stations Utah, Idaho, Nevada, California, Montana, and Colorado.”

The deceased had been called to go from Ogden, Utah, to Oakland, California, on account of the illness of his child. The child having died, he set out to return from Oakland to Ogden, and took the mail train in question with the knowledge of the train agent and conductor in charge, using as evidence of his right to transportation the com *607 mission above quoted. It was on this interstate journey that the train was derailed and the deceased came to his death as already mentioned.

The defense (so far as here pertinent) was that the deceased was not traveling upon any official business that entitled him to free transportation under'his commission, and that in riding free he was violating the act of Congress of June 29, 1906, commonly called the Hepburn Act (34 Stat. 584, 585, c. 3591, § 1), which forbids common carriers subject to the provisions of the act, after January 1,19Q7, to "directly or indirectly issue or give any interstate free ticket, free pass, or. free transportation for passengers, except ... to Railway Mail Service employés, post-office inspectors, customs inspectors and immigration inspectors; . . . and.any person, other than the persons exceptad in this provision, who uses any such interstate free ticket, free pass, or free transportation, shalllóe subject to a like penalty.” It was therefore contended that the deceased, was a trespasser, -and that the defendant was. under no legal duty to care for his safety.

In the trial court there was a verdict for the plaintiffs, and from the judgment thereon the present plaintiff in error appealed to the Utah Supreme Court, which at first reversed, and afterwards,. on a rehearing set aside the reversal and affirmed the judgment below; subsequently denying the company’s application for a new trial. 37 Utah, 581, 595, 612.

The court held that there was no evidence to support a finding that the deceased was traveling on appellant’s train in the discharge, or in pursuance, of duties pertaining to the Railway Mail Service; and that upon the evidence adduced the only permissible inference was that he left Ogden and went to Oakland solely on account of the death of his child, and that he was on the return journey of that mission when-the train was derailed.

But the court also found that the existence of the rela *608 tion of carrier and -'passenger between the deceased and the railroad company, and a breach of the duty of care for the passenger’s safety, resulting in his death, were so conclusively made to appear as to éntitle respondents to a directed verdict on those issues, so that certain errors committed by the trial court in the instructions to the jury became of no consequence. The court said: “That the car was derailed through the negligence of appellant as alleged in the complaint, and that the deceased was killed by reason of such derailment is, upon the record, not open to controversy. No substantial conflict is presented by the evidence on that subject.”

Upon the question of the relation of . carrier and passenger the court reasoned as follows: “ When he left Ogden he entered a mail car in appellant’s train. The evidence of his right to enter the mail car and be carried by'appellant was the commission issued to him, which, on its face, entitled him to transportation between all stations. in Utah, Nevada, and California. The commission, on its face, granted ‘the facilities of free transportation on the-lines named,’ regardless of . the. question whether he was or was not in the discharge of public duties. It was issued to him before the Hepburn Act took effect. The derailment and the deceased’s death occurred 14 days after the act took, effect. It was admitted by the parties on the trial that the deceased used the commission on the trip as ‘the evidence of his right to ride — the evidence of his right of transportation,’; — and that no question would be raised with respect to the exhibition of the commission to the conductor in charge of the train. The deceased, at Oakland, in the presence of the conductor and train agent, and with their knowledge, entered a mail car in a train • about to leave for Ogden, and impliedly with their consent, at least without their objection. In view of the stipulation, and upon’ the whole record, we think the only permissible inferences are, that the deceased, both in going *609 to and in returning from Oakland, rode in the mail car with the knowledge and consent of appellant’s conductors in charge of the train; that the appellant, its conductors and agents in charge of the train, and the deceased, in good faith, assumed and believed that the commission entitled him to so ride and to be transported in the mail car, regardless of the fact whether he was or was not on duty, and that the commission was so treated and so recognized by them, and as ‘the evidence of his right of transportation.’ There is nothing in the record to support the allegations in the answer.that the deceased entered the mail car without appellant’s knowledge or consent, or against its will, or with the intent, or for the purpose, of deceiving or defrauding' the appellant or' the Government, or that he otherwise entered the car clandestinely or fraudulently, or in bad faith, or with any wrongful design or purpose. The evidence, quite conclusively, shows the contrary. The deceased was, therefore, not á trespasser.”

In dealing with the questions of law arising from this state of facts, the court held, first, that the Hepburn Act does not forbid a carrier from giving free interstate transportation tó Railway Mail Service employes when not on duty and when .traveling for their own benefit or pleasure, and, secondly, "Though the construction which we have given the Hepburn Act should not be correct, and though it was unlawful for the appellant to give, and .the deceased to receive, free transportation on his commission, when he was not on duty, yet we are also of the opinion that, under all the circumstances of the case, the appellant, having undertaken and assumed to carry and txansport the deceased as a passenger by reason of the' commission, cannot escape liability for the consequences of its negligence on that ground.” And again: “We arc of the opinion that when a common carrier accepts a person as a passenger, he is not permitted to deny that he *610 owes to him the duty of diligence, prudence, and skill, which, as carrying on a public employment, he owes to all his passengers;' and that he cannot escape.liability for a negligent performance of that duty resulting in injury by urging that- the pass or • commission was issued, or the gratuitous passage permitted, by him, in violation of law.” As authority for this proposition the court cited Carroll v. Staten Island R. R. Co., 58 N. Y. 126; Del., Lack. & Western R. R. Co. v., Trautwein, 52 N. J. Law, 169; 7 L. R. A. 435; 5.Am. & Eng. Encyc. Law (2d ed.), 508, and other authorities.

It is plain that the decision adverse to the plaintiff in error was upon two independent grounds, the second ground being avowedly based upon the hypothesis that the court might be wrong,in its decision upon the'first.

Whether the Hepburn Act prohibits a carrier from giving free interstate transportation to the employés of the' Railway Mail Service when they are not on duty but are traveling for their own benefit or pleasure, is of course, a Federal question.

But whether — -assuming that question to be answered in the affirmative — the relation of carrier and passenger arises in the case of gratuitous passage under circumstances such as are presented in this case, is (in the absence of an act of Congress regulating the matter) a question not of Federal but of state law.

It is settled by numerous decisions of this court that where the' decision in the state court adverse to the plaintiff in error proceeds upon two independent grounds, one of which) not involving a Federal question, is sufficient to sustain the judgment, the writ of error will be dismissed or the judgmént affirmed, according to circumstances. Murdock v. City of Memphis, 20 Wall. 590, 635, 636; De Saussure v. Gaillard, 127 U. S. 216, 234; Hale v. Akers, 132 U. S. 554, 565; Hopkins v. McLure, 133 U. S. 380; Johnson v. Risk, 137 U. S. 300; Beaupre v. Noyes, *611 138 U. S. 397; Hammond v. Johnston, 142 U. S. 73, 78; Giles v. Teasley, 193 U. S. 146, 160; Allen v. Arguimbau, 198 U. S. 149, 154; Leathe v. Thomas, 207 U. S. 93, 98. In Murdock v. City of Memphis and Beaupre v. Noyes this court affirmed the judgments of the state court. In the other cases cited the writs of error were dismissed without considering the Federal questions.

Except for two contentions of the plaintiff in error now to be mentioned, a dismissal of the writ of error would necessarily follow: in the present case, since the second ground of decision adopted in the state court is manifestly independent of the first and is fully sufficient, to support the judgment; and except for what follows it involves no question of Federal right.

It is insisted (a) that there is no presumption that the railroad company violated the prohibition of the Hepburn Act by granting to Schuyler a free interstate ride, and that there is no evidence in the record to support such conclusion; and while it is conceded that ordinarily, upon writ of error to a state court, this court does not review the findings of fact, yet it is insisted that in this case a Federal right has been denied as the result of a finding of fact which is without support in the evidence; that the evidence is before us in the record by which that insistence may be tested; and that the status of Schuyler as an interstate passenger is a mixed question of law and fact so that it is incumbent upon us to analyze the evidence to the extent necessary to give to plaintiff in error the benefit of its asserted Federal right. The insistence as to the power and duty of this court in such a case is well founded. Kansas City Southern Ry. Co. v. Albers Commission Co., 223 U. S. 573, 591; Cedar Rapids Gas Co. v. Cedar Rapids, 223 U. S. 655, 668; Creswill v. Knights of Pythias, 225 U. S. 246, 261. We also agree there is no presumption that the railroad company gave free transportation, and that this was a fact to be established by evidence. Ac *612 cepting the duty to review this question of fact, we have examined the evidence in the record and find that it fairly supports the conclusion of the state court that the deceased was accepted by plaintiff in error as a gratuitous passenger.

But, finally, it is argued (6) that it was beyond the power of the state court to “read into the Hepburn Act an exception in favor of gratuitous passengers”; thereby (as is said) enlarging the class to whom Congress limited the right of free interstate transportation. This is ingenious,' but, as we think, unsound. As applied to the concrete case, it is equivalent to saying that the operation of the Hepburn Act is such as to deprive one who, in good faith and without fraud, and with the consent of the carrier, but in actual though unintentional violation of the prohibition of the act, accepts á free passage in interstate transportation, of the benefit of a rule of local law that renders the carrier in such circumstances responsible for exercising care for the passenger’s safety because the carrier has voluntarily undertaken the-burden of such care. But the act itself declares what penalty shall be imposed for a violation of its prohibition: “Any common carrier violating this provision shall be deemed guilty of a misdemeanor and for each offense, on conviction, shall pay to the United States a penalty of not less than one hundred dollars nor more than two thousand dollars, and any person, other than the persons excepted in this provision, who uses any such interstate free ticket, free pass or free transportation, shall be subject to a like penalty.” This penalty is not to be enlarged by construction. Neither the letter nor the spirit of the act makes an outlaw of him who violates its prohibition by either giving or accepting gratuitous interstate carriage. The deceased no more forfeited his life, limb or safety, and no more forfeited his right to the protection accorded by the local law to a passenger’in his situation, than the carrier *613 forfeited its right of property in the mail car upon which the deceased rode. His right to safe carriage was not derived, according to the láw of Utah, from the contract made between him and the carrier, and therefore was not deduced from the supposed violation of the Hepburn Act. It arose from the fact that he was a human being, of whose safety the plaintiff in error had undertaken the charge. With its consent he had placed his life in its keeping, and the local law thereupon imposed a duty upon'the carrier, irrespective of the contract of carriage. The Hepburn Act does not deprive one who accepts gratuitous carriage, under such circumstances, of the benefit and protection of the law of the State in this regard.

It results that the judgment under review must be affirmed, irrespective of the question whether the Hepburn Act forbids the. giving of free interstate transportation to the employés of the Railway Mail Service when not on duty.

Judgment affirmed.