MY DEAR SIR:— I have at length found, and now enclose, the letter to which you refer. I have very often spoken in the Senate on the subject of slavery in the different forms which the question has assumed, but have not the time at the present moment to look over the debates. I have recently received a letter from Governor Wright, of Indiana, who informs me it would be of great importance in that State should the _National Intelligencer_ come out in favor of the Democratic candidates. He had heard, as we have done, that such was the intention of its editors, after the adjournment of Congress. But they have at length come out in favor of Fremont. I say this, because they scout the idea that the Union would be in danger from his election...... Better they had at once raised the Republican flag. This opinion they have expressed, notwithstanding I am in the daily receipt of letters from the South, which are truly alarming, and these from gentlemen who formerly opposed both nullification and disunion. They say explicitly that the election of Fremont involves the dissolution of the Union, and this immediately. They allege that they are now looking on calmly for the North to decide their fate. When I say from the South, I refer to the States south of the Potomac. These evidences of public determination first commenced in the extreme South; but now the same calm and determined spirit appears to pervade Virginia. Indeed, the most alarming letter I have received has been from Virginia, and this, too, from a prudent, tranquil and able man, who has for some years been out of public life from his own choice. The remarks of the _National Intelligencer_ will either serve to delude the Northern people, or the Southrons are insincere. God save the Union! I do not wish to survive it. From your friend, very respectfully, JAMES BUCHANAN. P.S.—I refer to the article in the _Intelligencer_ of the 11th instant, headed, “The Balance Wheels of the Government.” One gentleman informs me that the men who were our contemporaries when the States lived in peace with each other, before the slavery excitement commenced, have passed away, and they have been succeeded by a new generation, who have grown up pending the slavery agitation. He says that they have been constantly assailed by the North, and now have as much hatred for the people of New England as the latter have for them; and many now deem that it would be for the mutual advantage of all parties to have a Southern Confederation, in which they can live at peace. I have received such communications with regret and astonishment. [TO A CITIZEN OF CALIFORNIA.] WHEATLAND, near LANCASTER, PENN., Sept. 17, 1856. SIR:—