This section is from the book "The Constitutional Law Of The United States", by Westel Woodbury Willoughby. Also available from Amazon: Constitutional Law.
In pursuance of the foregoing principles the Supreme Court of the United States has, from the very beginning, declared that the powers thus impliedly granted the General Government as necessary and proper for the exercise of the powers expressly given, are to be liberally construed. The words "necessary and proper," it was early held, were not to be interpreted as endowing the General Government simply with those powers indispensably necessary for the exercise of its express powers, but as equipping it with any and every authority the exercise of which may in any way assist the Federal Government in effecting any of the purposes the attainment of which is within its constitutional sphere. Thus in the case of the United States v. Fisher,6 decided in 1804, Marshall declared: "It would be incorrect and would produce endless difficulties if the opinion should be maintained that no law was authorized which was not indispensably necessary to give effect to a specified power. Where various systems might be adopted for that purpose, it might be said with respect to each that it was not necessary because the end might be obtained by other means. Congress might possess the choice of means which are in fact conducive to the exercise of a power granted by the Constitution."
6 2 Cr. 358: 2 L. ed. 304.