THE ten years of American history from 1850 to 1860 have a fascination second only to that of the four years which followed. Indeed, unless one has a taste for military science, it is a question whether the great war itself is more absorbing than the great debate that led up to it; whether even Gettysburg and Chickamauga, the March to the Sea, the Wilderness, Appomattox, are of more surpassing interest than the dramatic political changes, -the downfall of the Whig party, the swift rise and the equally swift submergence of the Know-Nothing party, the birth of the Republican party, the disruption and overthrow of the long-dominant Democratic party, -through which the country came at last to see that only the sword could make an end of the long controversy between the North and the Sout