In the debate in Congress on the resolution to censure John Quincy Adams, for presenting a petition for the dissolution of the Union, Mr. Underwood, of Kentucky, said: "They (the South) were the weaker portion, were in the minority. _The North could do what they pleased with them_; they could adopt their own measures. All he asked was, that they would let the South know what those measures were. One thing he knew well; that State, which he in part represented, had perhaps a deeper interest in this subject than any other, except Maryland and a small portion of Virginia. And why? Because he knew that to dissolve the Union, and separate the different States composing the confederacy, making the Ohio River and the Mason and Dixon's line the boundary line, _he knew as soon as that was done, Slavery was done_ in Kentucky, Maryland and a large portion of Virginia, and it would extend to all the States South of this line. _The dissolution of the Union was the dissolution of Slavery._ It has been the common practice for Southern men to get up on this floor, and say, 'Touch this subject, and we will dissolve this Union as a remedy.' _Their remedy was the destruction of the thing which they wished to save_, and any sensible man could see it. If the Union was dissolved into two parts, the slave would cross the line, and then turn round and curse the master from the other shore." The declaration of Mr. Underwood as to the entire dependence of the slave masters on the citizens of the nominally Free States to guard their plantations, and secure them against desertion, is substantially confirmed by Thomas D. Arnold, of Tennessee, who, in a speech on the name subject, assures us that they are equally dependent on the North for _personal protection_ against their slaves. In assigning his reasons for adhering to the Union, Mr. Arnold makes use of the following language: "The Free States had a majority of 44 in that House. Under the new census, they would have 53. The cause of the slaveholding States was getting weaker and weaker, and what were they to do? He would ask his Southern friends what the South had to rely on, if the Union were dissolved? Suppose the dissolution could be peaceably effected (if that did not involve a contradiction in terms), what had the South to depend upon? _All the crowned heads were against her. A million of slaves were ready to rise and strike for freedom at the first tap of the drum._ If they were cut loose from their friends at the North (friends that ought to be, and without them, the South had no friends), _whither were they to look for protection_? How were they to sustain an assault from England or France, with the cancer at their vitals? The more the South reflected, the more clearly she must see that she has a deep and vital interest in maintaining the Union."