In former messages I have expressed my conviction that the Constitution does not warrant the application of the funds of the General Government to objects of internal improvement which are not national in their character, and, both as a means of doing justice to all interests and putting an end to a course of legislation calculated to destroy the purity of the Government, have urged the necessity of reducing the whole subject to some fixed and certain rule. As there never will occur a period, perhaps, more propitious than the present to the accomplishment of this object, I beg leave to press the subject again upon your attention. Without some general and well-defined principles ascertaining those objects of internal improvement to which the means of the nation may be constitutionally applied, it is obvious that the exercise of the power can never be satisfactory. Besides the danger to which it exposes Congress of making hasty appropriations to works of the character of which they may be frequently ignorant, it promotes a mischievous and corrupting influence upon elections by holding out to the people the fallacious hope that the success of a certain candidate will make navigable their neighboring creek or river, bring commerce to their doors, and increase the value of their property. It thus favors combinations to squander the treasure of the country upon a multitude of local objects, as fatal to just legislation as to the purity of public men. If a system compatible with the Constitution can not be devised which is free from such tendencies, we should recollect that that instrument provides within itself the mode of its amendment, and that there is, therefore, no excuse for the assumption of doubtful powers by the General Government. If those which are clearly granted shall be found incompetent to the ends of its creation, it can at any time apply for their enlargement; and there is no probability that such an application, if founded on the public interest, will ever be refused. If the propriety of the proposed grant be not sufficiently apparent to command the assent of three-fourths of the States, the best possible reason why the power should not be assumed on doubtful authority is afforded; for if more than one-fourth of the States are unwilling to make the grant its exercise will be productive of discontents which will far overbalance any advantages that could be derived from it. All must admit that there is nothing so worthy of the constant solicitude of this Government as the harmony and union of the people.