This new agitation in Congress began about 1834-5 and was continued with great violence for several years, a petition being presented by Mr. Adams, during the time, for the dissolution of the Union. After much exasperation of feeling growing out of the presentation of the petitions in both Houses of Congress and the circulation of incendiary publications, some respite from the excitement in Congress was obtained by the adoption of a rule in the lower House for laying petitions on the table on their presentation, without debate, and by the conservative action of the Senate. The agitation, however was continued at the North and began to have an important influence upon the canvass for the presidential elections. The law for the recovery of fugitive slaves, always inefficient because of the refusal or failure of the states' officers to enforce it, had now become a dead letter by the resistance to its execution by mobs and the still more mischievous action of several of the legislatures of the free states. The circulation of incendiary publications through the mails had been forbidden by Congress, but the Northern press was prolific in the production of gross libels upon the character of the people of the Southern states and misrepresentations of the institution of slavery as it existed there; even the Constitution of the United States was denounced by the new lights as "a league with hell and a covenant with death."
Arkansas had been admitted as a slave state in the year 1836 and Michigan as a free state in 1837; and in 1845 Florida was admitted as a slave state, the same act providing for the admission of Iowa, which was a free state, but did not come in until 1846.
On the 29th of December, the independent Republic of Texas was admitted into the Union as a state, and came in with slavery already established there. This admission, or annexation as it was called, of Texas, resulted in the war with Mexico and the establishment, at the close of the war in 1848, of the Rio Grande as the southern boundary of Texas and the acquisition of the provinces or territories of New Mexico and upper California as United States territory.
The admission of Texas gave a new impulse to the antislavery agitation, and the acquisition, by the war, of the new territory brought it again prominently before Congress. Even before the close of the war with Mexico, the old proposition for the exclusion of slavery from the public territories was revived, with a view to its application to any territory that might be acquired as a result of the war, and it was then designated as the "Wilmot Proviso" from the name of the member re-introducing it. On all propositions to establish governments of the newly acquired territory, after the close of the war, the "Wilmot Proviso" was pressed with great vehemence by Northern politicians, and was strenuously resisted by those of the South.
The most extreme of the Southern politicians were willing to extend the so-called Missouri Compromise line of 36° 30´ to the Pacific ocean, and regard it as a final settlement of the question, but the Northern advocates of the proviso would listen to no terms for an adjustment, and thus again repudiated the principle and spirit of the settlement made by the Missouri bill. Southern statesmen, while willing to accept the line of 36° 30´ for the sake of peace, did not claim the right to foster slavery even upon the territory south of that line, by the action of Congress, but they claimed that the question should be left where the Constitution of the United States left it, that is, that the people settling in the territories should be allowed freedom to adopt their own institutions when they came to form state governments, and that Congress in the meantime should adopt no measures to forestall their action. They urged that the territory was acquired by the common blood and treasure, and that Congress, therefore, in its action, should not give preference to one section over another and thus virtually exclude the people of the South from the newly acquired domain. This was a reasonable and just view of the subject, and did not look to the increase of the number of slaves, but merely to their expansion over a wider area, and the older states from the rapidly increasing slave population. Nor was the proposition to exclude slavery ever in the interest of freedom, for it sought merely to confine slavery to the country where it already existed, and thus surround the slave states with a cordon of free states, so as to increase year by year, the difficulties of prospective emancipation, and render any but a subversion of the institution by violence an impossibility. It was as injurious to the slaves themselves as to the white population of the states.
Had the would-be philanthropists been governed by an enlightened regard for the welfare or freedom of the slaves, they would not have objected to their introduction, either into the territory north of 36° 30´ or that acquired from Mexico, for with the greater eagerness existing at the North for emigration, as well as that from foreign countries and the want of adaptation of the soil and climate of the greater part of the territory, old and new, to the staples in the production of which slave labor could be profitably employed, it was certain that much the larger population settling in that territory would be from the free states and foreign countries, and it was equally certain that, when the people came to form new states, slavery would be prohibited and freedom given to the slaves within the limits of most, if not all of those states.
But fanaticism of no kind, whether political or religious, listens to reason, and among the pseudo-philanthropists there was much of the leaven of that old spirit, which had prompted the hanging, burning and scourging of "heretics and witches."
There were many politicians by trade, whose aspirations had been unsuccessful and who cared nothing for the negro or the cause of freedom, but who fell in with the "free-soil" movement, as it was called with the selfish hope of building up a great sectional party under the auspices of which they could obtain and retain that power which they had failed to acquire otherwise. A very large mass of men rarely think for themselves and among this class the leaders of the "free-soil" operated extensively by impassioned appeals to their prejudices and passions, inducing them to believe that their vital interests required that slavery should be excluded by law from the territories. One of the shrewdest and most far-seeing of the "free-soil" leaders boldly declared that there was a "higher law" than the Constitution and that there was "an impassable conflict between slavery and freedom."
It cannot be denied that there were extreme men at the South on the other side, but they were made so mostly by the hostile attitude assumed by their opponents.
The result of the agitation was that for some time no government could be formed for any part of the new territory. The exasperation of feeling between the two sections of the Union, and the danger to that Union itself, became so great that in 1850 the more moderate of the leading statesmen of the country, with Clay and Webster at their head, devoted themselves to the adjustment of the threatening questions and their efforts resulted in the adoption of certain measures commonly called the "Compromise Measures of 1850." These measures consisted of a bill for the admission of California into the Union, under a constitution excluding slavery, which had been irregularly adopted a bill to establish a territorial government for Utah and a bill to establish the northern and western boundaries of Texas with her assent, and to establish a territorial government for New Mexico, it being provided in the territorial bills that states created out of the two territories organized when the population should be sufficient, should be admitted into the Union with or without slavery, as the people themselves might decide.