Congress, representing the proprietors of the territorial domain and charged especially with power to dispose of territory belonging to the United States, has for a long course of years, beginning with the Administration of Mr. Jefferson, exercised the power to construct roads within the Territories, and there are so many and obvious distinctions between this exercise of power and that of making roads within the States that the former has never been considered subject to such objections as apply to the latter; and such may now be considered the settled construction of the power of the Federal Government upon the subject. Numerous applications have been and no doubt will continue to be made for grants of land in aid of the construction of railways. It is not believed to be within the intent and meaning of the Constitution that the power to dispose of the public domain should be used otherwise than might be expected from a prudent proprietor and therefore that grants of land to aid in the construction of roads should be restricted to cases where it would be for the interest of a proprietor under like circumstances thus to contribute to the construction of these works. For the practical operation of such grants thus far in advancing the interests of the States in which the works are located, and at the same time the substantial interests of all the other States, by enhancing the value and promoting the rapid sale of the public domain, I refer you to the report of the Secretary of the Interior. A careful examination, however, will show that this experience is the result of a just discrimination and will be far from affording encouragement to a reckless or indiscriminate extension of the principle. I commend to your favorable consideration the men of genius of our country who by their inventions and discoveries in science and arts have contributed largely to the improvements of the age without, in many instances, securing for themselves anything like an adequate reward. For many interesting details upon this subject I refer you to the appropriate reports, and especially urge upon your early attention the apparently slight, but really important, modifications of existing laws therein suggested. The liberal spirit which has so long marked the action of Congress in relation to the District of Columbia will, I have no doubt, continue to be manifested.