Grant's mission in Mexico was finished. In that rapid and brilliant campaign from Vera Cruz to the capital, he had practically learned the lesson of war, and prepared himself for the great work he was to accomplish at a later period of his life, when West Point was to be divided between the opposing armies, when the most brilliant genius and the most determined energy alone could win victories. The importance of this season of actual duty in the field, in all the details of siege, march, and garrison duty, can hardly be over-estimated. In the war of the Great Rebellion he came into the field a trained soldier, with the teachings of experience stored up for use in a broader sphere of action than he or any of his companions in arms had yet dreamed of. After the ratification of the treaty of peace between Mexico and the United States, our forces evacuated Mexico, and Captain Grant was sent to New York with his regiment, where its companies were detached and sent to the forts on the northern frontier. Grant and his company were first stationed at Detroit, and then transferred to Sacketts Harbor. In 1848 he was married to Miss Dent, in conformity with the engagement made five years before, to which both had religiously adhered. The treaty of peace with Mexico had given us California, and coincident with the acquisition of the territory, gold was discovered there in such quantities as to attract an immense immigration, and it was necessary for the government to send out troops for the protection of the swarming hosts, both from themselves and from the Indians. The Fourth Infantry was sent to Oregon in 1851. The battalion in which Grant served was stationed at Fort Dallas, where the illustrious soldier obtained some further experience of Indian warfare. He was separated from his family, and in this wild region shut out from any employment worthy his nature, and apparently from all hope of rising either as a citizen or a soldier. It would have been surprising if Grant had not been discontented. He was a man of deeds, emphatically a man of action; but there was nothing to be done worthy his ambition. In 1853 he was promoted to a full captaincy; but this advancement could not relieve him from the tedium of such a stupid life, and the following year he resigned his commission, to enter upon a new and untried career in civil life. CHAPTER VII. _In which Captain Galligasken goes with the illustrious Soldier to the Farm near St. Louis, and observes his Career through various Misfortunes, till he is included in the Firm of Grant & Sons._