In view of the high and responsible duties which we owe to ourselves and to mankind, I trust you may be able at your present session to approach the adjustment of the only domestic question which seriously threatens, or probably ever can threaten, to disturb the harmony and successful operations of our system.

The immensely valuable possessions of New Mexico and California are already inhabited by a considerable population.  Attracted by their great fertility, their mineral wealth, their commercial advantages, and the salubrity of the climate, emigrants from the older States in great numbers are already preparing to seek new homes in these inviting regions.  Shall the dissimilarity of the domestic institutions in the different States prevent us from providing for them suitable governments?  These institutions existed at the adoption of the Constitution, but the obstacles which they interposed were overcome by that spirit of compromise which is now invoked.  In a conflict of opinions or of interests, real or imaginary, between different sections of our country, neither can justly demand all which it might desire to obtain.  Each, in the true spirit of our institutions, should concede something to the other.

Our gallant forces in the Mexican war, by whose patriotism and unparalleled deeds of arms we obtained these possessions as an indemnity for our just demands against Mexico, were composed of citizens who belonged to no one State or section of our Union.  They were men from slaveholding and nonslaveholding States, from the North and the South, from the East and the West.  They were all companions in arms and fellow-citizens of the same common country, engaged in the same common cause.  When prosecuting that war they were brethren and friends, and shared alike with each other common toils, dangers, and sufferings.  Now, when their work is ended, when peace is restored, and they return again to their homes, put off the habiliments of war, take their places in society, and resume their pursuits in civil life, surely a spirit of harmony and concession and of equal regard for the rights of all and of all sections of the Union ought to prevail in providing governments for the acquired territories—­the fruits of their common service.  The whole people of the United States, and of every State, contributed to defray the expenses of that war, and it would not be just for any one section to exclude another from all participation in the acquired territory.  This would not be in consonance with the just system of government which the framers of the Constitution adopted.

The question is believed to be rather abstract than practical whether slavery ever can or would exist in any portion of the acquired territory even if it were left to the option of the slaveholding States themselves.  From the nature of the climate and productions in much the larger portion of it it is certain it could never exist, and in the remainder the probabilities are it would not.  But however this may be, the question, involving, as it does, a principle of equality of rights of the separate and several States as equal copartners in the Confederacy, should not be disregarded.