Mr. Adams here, at considerable length, portrays the danger then existing of a war with Mexico, involving England and the European powers, bringing hostile armies and fleets to our own Southern territory, and inducing not only a foreign war, but an Indian, a civil, and a servile war, and making of the Southern States “the battle-field upon which the last great conflict will be fought between Slavery and Emancipation.”  “Do you imagine (he asks) that your Congress will have no constitutional authority to interfere with the institution of slavery, in any way, in the States of this Confederacy?  Sir, they must and will interfere with it—­perhaps to sustain it by war, perhaps to abolish it by treaties of peace; and they will not only possess the constitutional power so to interfere, but they will be bound in duty to do it, by the express provisions of the Constitution itself.  From the instant that your slaveholding States become the theatre of a war, civil, servile, or foreign, from that instant, the war powers of Congress extend to interference with the institution of slavery, in every way by which it can be interfered with, from a claim of indemnity for slaves taken or destroyed, to the cession of States burdened with slavery to a foreign power.”—­New York Tribune.

THE WAR IN ITS RELATION TO SLAVERY.

To the editor of the new York Tribune: 

Sir,—­Our country is opening up a new page in the history of governments.  The world has never witnessed such a spontaneous uprising of any people in support of free institutions as that now exhibited by the citizens of our Northern States.  I observe that the vexed question of slavery still has to be met, both in the Cabinet and in the field.  It has been met by former Presidents, by former Cabinets, and by former military officers.  They have established a train of precedents that may be well followed at this day.  I write now for the purpose of inviting attention to those principles of international law which are regarded by publicists and jurists as proper guides in the exercise of that despotic and almost unlimited authority called the “war power.”  A synopsis of these doctrines was given by Major General Gaines, at New Orleans, in 1838.

General Jessup had captured many fugitive slaves and Indians in Florida, and had ordered them to be sent west of the Mississippi.  At New Orleans, they were claimed by the owners, under legal process; but Gen. Gaines, commanding that military district, refused to deliver them to the sheriff, and appeared in court, stating his own defence.

He declared that these people (men, women and children) were captured in wars and held as prisoners of war:  that as commander of that military department or district, he held them subject only to the order of the National Executive:  that he could recognize no other power in time of war, or by the laws of war, as authorized to take prisoners from his possession.