The power to regulate commerce, vested in congress, is the power to preserlbe the rules by which it shall be governed, that is, the condltlons upon whlch it shall be conducted, to determlne when it shall be free, and when subject to duties or other exactions. Tbe power also embraces within lts control all the instrumentalltles hy which that commerce may be carrled on, and the means by whlch it may be aided and en-couraged. Gloucester Ferry Co. v. Pennsyl-vania, 114 U. S. 196, 5 Sup. Ct. 826, 29 L. Ed. 158. And see Gibbons v. ogden, 9 wheat. 227, 6 L. Ed. 23 ; Gilman v. Phlladelphla, 3 wall. 724, 18 L. Ed. 96; welton v. Mlssourl. 91 U. S. 279, 23 L. Ed. 347; Leisy v. Hardin, 135 U. S. 100, 10 Sup. Ct 681, 34 L. Ed. 128; Kavanaugh v. Southern R. Co., 120 Ga. 62, 47 S. E. 526
Source: Black's Law Dictionary 2nd Ed (1910)
