Nullification was half-throttled by Jackson's proclamation, half-quieted by Clay's compromise. But from that time forward the phraseology and the spirit of disunion became constant factors in Congressional debate and legislation. In 1850, it broke out to an extent and with an intensity never before reached. This time it enveloped the whole country, and many of the wisest and best statesmen believed civil war at hand. The compromise measures of 1850 finally subdued the storm; but not till the serious beginning of a secession movement had been developed and put down, both by the general condemnation of the whole country, and the direct vote of a union majority in the localities where it took its rise. Among these compromise acts of 1850 was the admission of California as a free-State. The gold discoveries had suddenly filled it with population, making the usual probation as a Territory altogether needless. A considerable part of the State lay south of the line of 36º, 30', and the pro-slavery extremists had demanded that it should be divided into two States--one to be a free and the other to be a slave-State--in order to preserve the political balance between the sections, in the United States Senate. This being refused, they not only violently opposed the compromise measures, but organized a movement for resistance in South Carolina, Georgia, and Mississippi, demanding redress, and threatening secession if it were not accorded. A popular contest on this issue followed in 1851 in these States, in which the ultra-secession party was signally overthrown. It submitted sullenly to its defeat; leaving, as always before, a considerable faction unsatisfied and implacable, only awaiting a new opportunity to start a new disturbance. This new opportunity arose in the slavery agitation, beginning with the repeal of the Missouri Compromise in 1854, and ending with the election of Lincoln. Daring this six years' controversy, disunion was kept in the background because the pro-slavery party had continual and sanguine hope of ultimate triumph. It did not despair of success until the actual election of Lincoln, on the 6th of November, 1860; consequently, even in the Southern States, as a rule, disunion was frowned upon till near the end of the Presidential campaign, and only paraded as an evil to be feared, not as a thing to be desired. This aspect, however, was superficial. Under the surface, a small but determined disunion conspiracy was actively at work. It has left few historical traces; but in 1856 distinct evidence begins to crop out. There was a possibility, though not a probability, that Frémont might be elected President; and this contingency the conspirators proposed to utilize by beginning a rebellion. A letter from the Governor of Virginia to the Governors of Maryland and other States is sufficient proof of such an intent, even without the evidence of later history. RICHMOND, VA., Sept. 15, 1856.