"Whoever will candidly examine the reports of the commission from year to year, and thus become acquainted with the work which has been done and is now going on, will have no doubt of the potential value of this enactment in correcting public sentiment, restraining public injustice and enforcing the principle of reasonable charges and equal treatment. Imperfections and weaknesses which could not be anticipated at the time of its passage have since been disclosed by the effort to give it effective administration. The test of experience, so far from condemning the policy of public regulation, has established, its importance and intensified its necessity. The very respects in which the existing law has failed to meet public expectation point out the advantages and demonstrate the utility of Government supervision.... "Of this much we are convinced: The public demand for Government regulation and the necessity for legal protection against the encroachments of railroad corporations have not been diminished by the experience of the last six years. The act to regulate commerce was not framed to meet a temporary emergency, nor in obedience to a transient and spasmodic sentiment. The people will not tolerate a return to the injustice and wrong-doing which inevitably occurs when no correction is undertaken and no regulation attempted. The evils of unrestricted management will not be permanently endured, and legal remedies will continue to be sought until they are amply provided. The present statute, however crude and inadequate in many respects, was the constitutional exercise of most important powers and the legislative expression of a great and wholesome principle. Its fundamental and pervading purpose is to secure equality of treatment. It assumes that the railroads are engaged in a public service, and requires that service to be impartially performed. It asserts the right of every citizen to use the agencies which the carrier provides on equal terms with all his fellows, and finds an invasion of that right in every unauthorized exemption from charges commonly imposed.