opinion: Mr. Justice Minton
  delivered the opinion of the Court.
  The question we have for decision here is whether petitioner, a clerical employee of respondent railroad, is within the coverage of the Federal Employers’ Liability Act. § 1, 35 Stat. 65, as amended, 53 Stat. 1404, 45 U. S. C. § 51. Petitioner is employed entirely in respondent’s office building in Philadelphia. Her duties consist of filing original tracings of all of respondent’s engines, cars, parts, tracks, bridges, and other structures, from which blueprints of those items are made. There are some 325,000 tracings on file in the office in which petitioner works. Whenever an order for blueprints comes in from anywhere in respondent’s system, it is petitioner’s responsibility to fill the order by securing the correct tracings from the files. These she takes to the blueprint maker in the same office building. After the blueprints are made, it is petitioner’s further duty to return the original tracings to the appropriate file. About 67% of the blueprints so made are sent to points outside Pennsylvania. The files which petitioner attends are the sole depository of the original tracings of the structural details of all of respondent’s rolling stock, trackage, and other equipment and installations, and as such represent a fund of documents without which maintenance of the operating system would be impossible.
  Petitioner was injured when a cracked window pane in her office blew in upon her. She brought suit for personal injury under the Federal Employers’ Liability Act. On respondent’s motion to dismiss, the District Court held that petitioner was not within the coverage of § 1 of the Act and, there being no diversity of citizenship between the parties, dismissed the complaint for lack of jurisdiction. The Court of Appeals affirmed. 227 F. 2d 810. We granted certiorari because of the importance of the question presented in the administration of the Act. 350 U. S.965.
  As originally enacted, § 1 provided that every railroad, “while engaging” in interstate commerce,
  “shall be liable in damages to any person suffering injury while he is employed by such carrier in such commerce ... for such injury or death resulting in whole or in part from the negligence of any of the officers, agents, or employees of such carrier, or by reason of any defect or insufficiency, due to its negligence, in its cars, engines, appliances, machinery, track, roadbed, works, boats, wharves, or other equipment.” 35 Stat. 65.
  A further paragraph was added to the section in 1939, and it is clear that two specific problems which the amendment sought at least to remedy were the results of this Court’s holdings that, at the moment of his injury, the employee as well as the railroad had to be engaged in interstate commerce in order to come within the coverage of § 1, and that employees engaged in construction of new facilities were not covered. S. Rep. No. 661, 76th Cong., 1st Sess. 2-3; Southern Pacific Co. v. Gileo, decided today, ante, p. 493. The amendment took the form of an expanded definition of “person . . . employed” in interstate commerce. The amendment reads:
  “Any employee of a carrier, any part of whose duties as such employee shall be the furtherance of interstate or foreign commerce; or shall, in any way directly or closely and substantially, affect such commerce as above set forth shall, for the purposes of this Act, be considered as being employed by such carrier in such commerce and shall be considered as entitled to the benefits of this Act . . . .” 53 Stat. 1404.
  No argument is made that Congress could not constitutionally include petitioner within the coverage of the Act. The argument is that the amendment was narrowly drawn to remedy specific evils and that to construe it to include petitioner would amount to inclusion in the Act of virtually all railroad employees — a result which respondent assumes is unintended and undesirable. The argument takes several forms. First, it is said that “commerce” in the Act means only transportation and that petitioner is not employed in transportation. See Shanks v. Delaware, L. & W. R. Co., 239 U. S. 556, 559-560. But the interstate commerce in which respondent is engaged is interstate transportation. If “any part” of petitioner’s duties is in “furtherance” of or substantially affects interstate commerce, it also is in “furtherance” of or substantially affects interstate transportation. The. test for coverage under the amendment is not whether the employee is engaged in transportation, but rather whether what he does in any way furthers or substantially affects transportation. Nor can we resolve the issue presented here in terms of whether or not clerical employees as a class are excluded from the benefits of the statute. The 1939 amendment was designed to obliterate fine distinctions as to coverage between employees who, for the purpose of this remedial legislation, should be treated alike. There is no meaningful distinction, in terms of whether the employee’s duties are clerical or not, between petitioner and, for illustration, an assistant chief timekeeper, Straub v. Reading Co., 220 F. 2d 177, or a messenger boy carrying waybills and grain orders between separate local offices and freight stations, Bowers v. Wabash R. Co., 246 S. W. 2d 535, or a lumber inspector hurt while inspecting ties at a lumber company, Ericksen v. Southern Pacific Co., 39 Cal. 2d 374, 246 P. 2d 642 — all of whom have been held covered by the 1939 amendment. See also Lillie v. Thompson, 332 U. S. 459. Nor are the benefits of the Act limited to those exposed to the special hazards of the railroad industry. The Act has not been so interpreted, and the 1939 amendment specifically affords protection to “any employee” whose duties bring him within that amendment. There is no basis in the language of § 1 for confining liability of the railroad so as to exclude any class of railroad employees as a class. The benefits of the Act are not limited to those who have cinders in their hair, soot on their faces, or callouses on their hands. Section 1 cannot be interpreted to exclude petitioner from its benefits without further consideration of the function she performs and its impact on interstate commerce.
  We think that the present petitioner is employed by the respondent in interstate commerce within the meaning of the 1939 amendment to § 1. Although the amendment may have been prompted by a specific desire to obviate certain court-made rules limiting coverage, the language used goes far beyond that narrow objective. It evinces a purpose to expand coverage substantially as well as to avoid narrow distinctions in deciding questions of coverage. Under the amendment, it is the “duties” of the employee that must further or affect commerce, and it is enough if “any part” of those duties has the requisite effect. The statute commands us to examine the purpose and effect of the employee’s function in the railroad’s interstate operation, without limitation to nonclerical employees or determination on the basis of the employee’s importance as an individual in the railroad’s organization.
  Here respondent railroad has chosen to arrange its operations so that repairs and construction anywhere within its system which require blueprints must go through its Philadelphia office. No such work can be done without recourse to the files of 325,000 original tracings in petitioner’s custody. Loss or misplacing of those tracings could promptly cause delay, confusion, or worse in the day-to-day operation of respondent’s lines. If all employees who perform petitioner’s duties were removed from service, respondent could not conduct its operations without a change in its organizational system. To recognize this is to attribute to petitioner neither an exaggerated nor an attenuated relationship to respondent’s transportation system. The filing of tracings and the dispatch of blueprints taken from them comprise a direct link in the maintenance of respondent’s lines and rolling stock. Together with the makers of blueprints, petitioner constitutes the means by which men throughout respondent’s system obtain the information they must have to maintain the railroad’s trains, equipment, track, and structures.
  The very purpose of petitioner’s job is to further physical maintenance of an interstate railroad system. Proper performance of her duties makes an obvious contribution to the maintenance of that system. We hold that the petitioner, by the performance of her duties, is furthering the interstate transportation in which the respondent is engaged. “The word ‘furtherance’ is a comprehensive term. Its periphery may be vague, but admittedly it is both large and elastic.” Shelton v. Thomson, 148 F. 2d 1, 3. Petitioner’s duties here come within the confines of that concept.
  Similarly, those duties which “in any way directly or closely and substantially affect” interstate commerce in the railroad industry must necessarily be marked out through the process of case-by-case adjudication. This definition and the “furtherance” definition of employment in interstate commerce in the 1939 amendment are set forth in the disjunctive. In some situations they may overlap. Here we hold that, for the reasons already given, performance of petitioner’s duties has a' close and substantial effect upon the operation of respondent’s interstate activities. Cf. Overstreet v. North Shore Corp., 318 U. S. 125.
  Petitioner’s duties brought her within the coverage of § 1 as amended, and the District Court therefore had jurisdiction over this suit under the Federal Employers’ Liability Act. The judgment below is reversed and the cause remanded to the District Court for further proceedings.
  Reversed.
  Mr. Justice Burton dissents for the reasons stated below in the opinion of the Court of Appeals.