MR. JUSTICE MARSHALL delivered the opinion of the Court.

The petitioners in this case attack their convictions under the Travel Act, 18 U.S.C. § 1952, which makes it unlawful to use a facility of interstate commerce in furtherance of certain criminal activity. Petitioners were tried in five separate trials. The cases were consolidated for purposes of appeal since each raised the question whether causing a publication to be carried by a facility of interstate commerce with an intent to facilitate the operation of a gambling business illegal under state law violated § 1952. The Court of Appeals for the Seventh Circuit affirmed the convictions, finding no exception in § 1952 for the transmittal of publications. 452 F.2d 967 (1971). We granted certiorari for the limited purpose of resolving the conflict between this decision and a previous ruling of the Court of Appeals for the Fourth Circuit. 405 U.S. 973 (1972). For reasons stated below, we affirm.

In all respects here relevant, the facts of the five cases are identical. Each involves the operation in Hammond, Indiana, of a bookmaking business. A publication known as the Illinois Sports News was important to the functioning of each bookmaking operation. The News, a publication of the type generally referred to as a "scratch sheet," contains more complete and detailed horse racing information than is found in regular newspapers, and was used extensively by the customers of the five bookmaking operations in placing their bets. Because the News, which appears daily except Sunday, is published in Chicago, Illinois, it was necessary to make arrangements for prompt daily delivery from Chicago to Hammond and the bookmaking establishments. This was accomplished by causing copies of the News to be placed on board an early morning train of the Chicago, South Shore, South Bend Railroad in Chicago for delivery to the railroad station in Hammond, where copies were picked up for each of the bookmaking operations. In each case the petitioners assumed various roles in this scheme, but the pattern of the scheme for securing the prompt daily delivery of the News was the same in all cases.

Section 1952(a) subjects to criminal liability anyone who "uses any facility in interstate . . . commerce . . . with intent to . . . promote, manage, establish, carry on, or facilitate the promotion, management, establishment, or carrying on, of any unlawful activity, and thereafter performs or attempts to perform any of [these] acts . . . ." Unlawful activity includes "any business enterprise involving gambling . . . offenses in violation of the laws of the State in which they are committed . . . ." See 18 U.S.C. § 1952 (b). For our limited purposes it is not open to dispute that in each case petitioners were involved in bookmaking businesses which violated Indiana law; that the Illinois Sports News was important to the operation of those bookmaking businesses; that the scheme for delivery of the News — a scheme which involved the use of a facility of interstate commerce, the railroad — was intended to facilitate the operation of the bookmaking businesses; or that the requisite overt acts occurred following the use of the interstate facility. The only question here is whether these cases fall outside the ambit of § 1952 because the use of the interstate facility was to secure delivery of a news publication.

The basis of petitioners' challenge to the legality of their convictions under § 1952 — and of the conflict between the courts of appeals — is to be found in 18 U.S.C. § 1953. Section 1953(a) makes it unlawful for anyone, "except a common carrier in the usual course of its business, knowingly [to] carr[y] or [to send] in interstate . . . commerce any . . . paraphernalia, . . . paper, writing, or other device used, or to be used . . . in (a) bookmaking; or (b) wagering pools . . .; or (c) in a numbers, policy, bolita, or similar game . . . ." The broad sweep of subsection (a) in terms of paraphernalia covered is limited to some extent by § 1953(b)(3) which makes the section inapplicable to "the carriage or transportation in interstate . . . commerce of any newspaper or similar publication."

Petitioners' argument starts from the premise that they could not have been prosecuted under § 1953(a) because the Illinois Sports News falls within the newspaper exception contained in § 1953(b)(3). Petitioners recognize that § 1952 contains no express exception for newspapers comparable to § 1953(b)(3), but contend that § 1952 and § 1953 are in pari materia — that is, pertain to the same subject — and, under settled principles of statutory construction, should therefore be construed "as if they were one law," United States v. Freeman, 3 How. 556, 564 (1845); see, e.g., United States v. Stewart, 311 U.S. 60, 64 (1940); Estate of Sanford v. Commissioner, 308 U.S. 39, 44 (1939). Thus, petitioners would have us read the exception contained in § 1953(b)(3) as applicable to not only § 1953(a) but also § 1952(a), thereby barring their prosecution under the latter as well as the former. This we cannot do.

The rule of in pari materia — like any canon of statutory construction — is a reflection of practical experience in the interpretation of statutes: a legislative body generally uses a particular word with a consistent meaning in a given context. Thus, for example, a "later act can . . . be regarded as a legislative interpretation of [an] earlier act . . . in the sense that it aids in ascertaining the meaning of the words as used in their contemporary setting," and "is therefore entitled to great weight in resolving any ambiguities and doubts." United States v. Stewart, supra, at 64-65. See also, e.g., Hunter v. Erickson, 393 U.S. 385, 388 (1969); United States v. Freeman, supra, at 565. The rule is but a logical extension of the principle that individual sections of a single statute should be construed together, for it necessarily assumes that whenever Congress passes a new statute, it acts aware of all previous statutes on the same subject, cf. Allen v. Grand Central Aircraft Co., 347 U.S. 535, 541-552 (1954). Given this underlying assumption, the rule's application certainly makes the most sense when the statutes were enacted by the same legislative body at the same time. Such was indeed the case here. Yet petitioners would have us resort to the exception contained in § 1953(b)(3) not simply to resolve any "ambiguities [or] doubts" in the language in § 1952 but to introduce an exception to the coverage of the latter where none is now apparent. This might be a sensible construction of the two statutes if they were intended to serve the same function, but plainly they were not.

True, § 1952 and § 1953 were both parts of a comprehensive federal legislative effort to assist local authorities in dealing with organized criminal activity which, in many instances, had assumed interstate proportions and which in all cases was materially assisted in its operations by the availability of facilities of interstate commerce. The two statutes, however, play different roles in achieving these broad, common goals.

Section 1953 has a narrow, specific function. It erects a substantial barrier to the distribution of certain materials used in the conduct of various forms of illegal gambling. By interdicting the flow of these materials to and between illegal gambling businesses, the statute purposefully seeks to impede the operation of such businesses.

Section 1952, by contrast, does not apply just to illegal gambling; rather, it is concerned with a broad spectrum of "unlawful activity," illegal gambling businesses being only one element. Moreover, the statute does not focus upon any particular materials, but upon the use of the facilities of interstate commerce with the intent of furthering an unlawful "business enterprise." It is, in short, an effort to deny individuals who act for such a criminal purpose access to the channels of commerce. Thus, while § 1952 ultimately seeks, like § 1953, to inhibit organized criminal activity, it takes a very different approach to doing so. To introduce into § 1952 an exception based upon the nature of the material transported in interstate commerce would carve a substantial slice from the intended coverage of the statute. This we will not do without an affirmative indication — which is lacking here — that Congress so intended.

Our conclusion here is bolstered by the fact that the reason for the newspaper exception to § 1953 is absent in the context of § 1952. The original version of § 1953 introduced in the Senate contained none of the exceptions set forth in subsection (b). It was quickly realized that the bill, as introduced, bore the potential for unreasonably broad application, since it would have imposed absolute criminal liability on anyone, except a common carrier, who "knowingly carries or sends in interstate . . . commerce" any gambling paraphernalia used in an illegal gambling business. Were "knowingly" construed as modifying only the phrase "carries or sends," the statute might have been applied to a wholly innocent person who knowingly carried a newspaper in interstate commerce unaware that it contained racing information. It was to avoid this problem that the newspaper exception was added to § 1953. But § 1952 obviously poses no threat to innocent citizens. Its application is limited to those who act with an intent to further unlawful activity — as was clearly true of these petitioners. There is, then, no reason for carrying the newspaper exception of § 1953(b)(3) over to § 1952.

The Judgment is

Affirmed.

MR. JUSTICE WHITE took no part in the decision of this case.