As slavery was prohibited under Mexican law, this territory must by the law of nations remain free until slavery was, by positive enactment, authorized therein. This ancient and universal law, however, was soon to be disregarded or denied by the advocates of the doctrine that the Constitution of the United States spread itself over territories, and, by force of it, legalized human slavery therein, and guaranteed to citizens of a State the right to carry their property--human slaves included--into United States territory and there hold it, by force of and protected by the Constitution, in defiance of unfriendly territorial or Congressional legislation. This novel claim also sprung from the brain of Calhoun, and was met with the true view of slavery, to wit: That it was a creature solely of law; that it existed nowhere of natural right; that whenever a slave was taken from a jurisdiction where slaves could be held by law, to one where no law made him a slave, his shackles fell off and he became a free man. The soundness of the rule that a citizen of a State could carry his personal property from his State to a Territory was admitted, but it was claimed he could not hold it there if it were not such as the laws of the Territory recognized as property. In other words, he might transfer his property from a State to a Territory, but he could not take with him the law of his State authorizing him to hold it as property. The law of the _situs_ is of universal application governing property. It remains to briefly note the effort to extend and interpret the Constitution, with the sole view to establish and perpetuate human slavery. Near the close of the session of Congress (1848-49), Mr. Walker of Wisconsin, at the instigation of Calhoun moved, as a rider on an appropriation bill, a section providing a temporary government for such Territories, including a provision to "_extend the Constitution of the United States to the Territories_." This astounding proposition was defended by Calhoun, and, with his characteristic straightforwardness, he avowed the true object of the amendment was to override the anti-slavery laws of the Territories, and plant the institution of slavery therein, beyond the reach of Congressional or territorial law. Mr. Webster expounded the Constitution and combated the newly brought forward slave-extension doctrine, but a majority of the Senate voted for the amendment. The House, however, voted down the rider, and between the two branches of Congress it failed. For a time appropriations of necessary supplies for the government were made to depend on the success of the measure.(64) Thus again the newly acquired domain escaped the doom of perpetual slavery. But we have done with the Mexican War and the acquisition of Mexican territory. It remains to be told how this vast domain was disposed of. No part of it ever became slave.