Mr. Justice Rehnquist delivered the opinion of the Court.
Petitioner brought suit in the state trial court of Georgia seeking damages for alleged “wrongful discharge” by the respondent. He alleged that prior to an auto accident in 1967, he had been an employee in good standing of the respondent, employed “under specified conditions and with a stipulated schedule of benefits.” He alleged that following the accident, he had fully recovered and was physically able to resume his work for respondent, but that respondent had refused to allow him to return to work, and that respondent’s actions amounted to a wrongful discharge. He prayed for damages consisting of loss of past and future earnings and for attorneys’ fees. Respondent removed the case to the United States District Court and there moved to dismiss the complaint for failure to exhaust the remedies provided by the § 3 First (i) of the Railway Labor Act, 44 Stat. 679, as amended, 48 Stat. 1191, 46 U. S. C. § 153 First (i). See also 1966 amendments to § 3 Second, 80 Stat. 208. The District Court granted the motion, and the Court of Appeals for the Fifth Circuit affirmed. We granted certiorari, 404 U. S. 955, and are once more confronted with the question of whether Moore-v. Illinois Central B. Co., 312 U. S. 630 (1941), should be overruled.
Moore held that a railroad employee who elected to treat his employer’s breach of the employment contract as a discharge was not required to resort to the remedies afforded under the Railway Labor Act for adjustment and arbitration of grievances, but was free to commence in state court an action based on state law for breach of contract. The result was supported by the Court’s conclusion that the procedures for adjustment of “minor disputes” under the Railway Labor Act had been intended by Congress to be optional, not compulsory, and that therefore a State was free- to accord an alternative remedy to a discharged railroad employee under its law of contracts. The basic holding of Moore was reaffirmed and its state law aspects amplified in Transcontinental & Western Air, Inc. v. Koppal, 345 U. S. 653 (1953). There it was held that if state law required the employee to exhaust administrative remedies provided for in his contract of employment before resorting to court, a federal diversity court should enforce that requirement.
Later cases from this Court have repudiated the reasoning advanced in support of the result reached in Moore v. Illinois Central, supra. Fifteen years ago, in Brotherhood of Railroad Trainmen v. Chicago R. & I. R. Co., 353 U. S. 30, 39 (1957), this Court canvassed the relevant legislative history and said:
“This record is convincing that there was general understanding between both the supporters and the opponents of the 1934 amendment that the provisions dealing with the Adjustment Board were to be considered as compulsory arbitration in this limited field.”
When the issue was again before the Court in Walker v. Southern R. Co., 385 U. S. 196 (1966), it was observed:
“Provision for arbitration of a discharge grievance, a minor dispute, is not a matter of voluntary agreement under the Railway Labor Act; the Act compels the parties to arbitrate minor disputes before the National Railroad Adjustment Board established under the Act.” 385 U. S., at 198.
Thus, the notion that the grievance and arbitration procedures provided for minor disputes in the Railway Labor Act are optional, to be availed of as the employee or the carrier chooses, was never good history and is no longer good law.
The related doctrine expressed in Moore and Koppal, that a railroad employee’s action for breach of an employment contract is created and governed by state law, has been likewise undercut by later decisions. In Machinists v. Central Airlines, 372 U. S. 682 (1963), an agreement required under § 204 of the Railway tabor Act was said to be “like the Labor Management Relations Act § 301 contract ... a federal contract and . . . therefore governed and enforceable by federal law, in the federal courts.” 372 U. S., at 692. A similar result was reached under § 301 (a) of the Labor Management Relations Act in Textile Workers v. Lincoln Mills, 353 ü. S. 448 (1957).
In Republic Steel Corp. v. Maddox, 379 U. S. 650 (1965), the Court deduced from the Labor Management Relations Act a preference for the settlement of disputes in accordance with contractually agreed-upon arbitration procedures. It accordingly held that before a state court action could be maintained for breach of such a contract, the employee must first “attempt use of the contract grievance procedure agreed upon by employer and union as the mode of redress.” 379 U. S., at 652. In Maddox, the Court not only refused to extend Moore- to save state court actions for breach of contract under § 301 of the Labor Management Relations Act, but intimated that its rule might well not survive even in Railway Labor Act cases. Indeed, since the compulsory character of the administrative remedy provided by the Railway Labor Act for disputes such as that between petitioner and respondent stems not from any contractual undertaking between the parties but from the Act itself, the case for insisting on resort to those remedies is if anything stronger in cases arising under that Act than it is in cases arising under § 301 of the LMRA.
The fact that petitioner characterizes his claim as one for “wrongful discharge” does not save it from the Act’s mandatory provisions for the processing of grievances. Petitioner argues that his election to sever his connection with the employer and treat the latter’s alleged breach of the employment contract as a “discharge” renders his claim sufficiently different from the normal disputes over the interpretation of a collective-bargaining agreement to warrant carving out an exception to the otherwise mandatory rule for the submission of disputes to the Board. But the very concept of “wrongful discharge” implies some sort of statutory or contractual standard that modifies the traditional common-law rule that a contract of employment is terminable by either party at will. Here it is conceded by all that the only source of petitioner’s right not to be discharged, and therefore to treat an alleged discharge as a “wrongful” one that entitles him to damages, is the collective-bargaining agreement between the employer and the union. Respondent in this case vigorously disputes any intent on its part to discharge petitioner, and the pleadings indicate that the disagreement turns on the extent of respondent’s obligation to restore petitioner to his regular duties following injury in an automobile accident. The existence and extent of, such an obligation in a case such as this will depend on the interpretation of the collective-bargaining agreement. Thus petitioner’s claim, and respondent’s disallowance of it, stem from differing interpretations of the collective-bargaining agreement. The fact that petitioner intends to hereafter seek employment elsewhere does not make his present claim against his employer any the less a dispute as to the interpretation of a collective-bargaining agreement. His claim is therefore subject to the Act’s requirement that it be submitted to the Board for adjustment.
The constitutional issue discussed in the dissent was not set forth as a “question presented for review” in the petition for certiorari, and therefore our Rule 23 (1) (c) precludes our consideration of it. “We do not reach for constitutional questions not raised by the parties.” Mazer v. Stein, 347 U. S. 201, 206 n. 5 (1954).
The term “exhaustion of administrative remedies” in its broader sense may be an entirely appropriate description of the obligation of both the employee and carrier under the Railway Labor Act to resort to dispute settlement procedures provided by that Act. It is clear, however, that in at least some situations the Act makes the federal administrative remedy exclusive, rather than merely requiring exhaustion of remedies in one forum before resorting to another. A party who has litigated an issue before the Adjustment Board on the merits may not relitigate that issue in an independent judicial proceeding. Union Pacific R. Co. v. Price, 360 U. S. 601 (1959). He is limited to the judicial review of the Board’s proceedings that the Act itself provides. Gunther v. San Diego & A. E. R. Co., 382 U. S. 257 (1965). In such a case the proceedings afforded by 45 U. S. C. § 153 First (i), will be the only remedy available to the aggrieved party.
In Walker v. Southern R. Co., 385 U. S. 196 (1966), the Court noted that there had been complaints not only about the long delay in processing of grievances on the part of the Adjustment Boards, but also about the fact that a more extensive right of judicial review of Board action was accorded to carriers than to employees. The Court noted that Congress, by Public Law 89-456, 80 Stat. 208, effective June 20, 1966, had legislated to correct these difficulties, but observed that the employee in Walker had not had the benefit of these new procedures. It therefore declined, “in his case,” 385 U. S., at 199, to overrule Moore. Petitioner Andrews, however, would in the prosecution of his claim before the Adjustment Board have the benefit of these improved procedures. We now hold that he must avail himself of them, and in so doing we necessarily overrule Moore v. Illinois Central R. Co., supra.
Affirmed.
Mr. Justice Powell took no part in the consideration or decision of this case.
References throughout the opinion to respondent are to the Georgia Railroad Co., which consisted of properties leased by Louisville & Nashville Railroad Co. and Seaboard Coastline Railroad Co. The petitioner alleged in his complaint that the Georgia Railroad Co. had refused to allow him to return to work.