The end of the Mexican War left Grant in a sort of quandary. He was not ready to be a businessman, so he did not follow the example of most of his West Point classmates and resign from the Army. Instead, he began a career in the peacetime Army, after marrying Julia Dent in August 1848. In an odd quirk of fate, the three groomsmen in his wedding would later serve in the Confederate Army that surrendered to Grant at Appamattox.
In October 1848, Grant returned to the Army and was ordered to report to Detroit–this time, however, he took Julia with him. When they arrived in Michigan, Grant discovered that his orders had been changed and that he needed to report to Sackets Harbor, New York, on the eastern shore of Lake Ontario. Grant protested, but the order to allow him to stay in Detroit did not arrive until Grant and his wife had reached Sackets Harbor, where they wintered.
The two became a model household in camp: Julia set up a nice living arraignment and Grant began giving her an allowance to hire a cook–a sign of prestige that Julia desperately wanted. However, she returned home to St. Louis soon after the couple arrived back in Detroit in the spring of 1849. Julia was pregnant and wanted to have the child with her family. On May 30, 1850, Julia gave birth to Frederick Dent Grant, who quickly became one of the most important people in Grant's life. His son was beside him at Vicksburg, later attended West Point, and served as the family spokesperson when Grant died many years later.
A year after Frederick's birth, Grant's regiment was transferred to the Pacific coast–a godsend of a posting in the mind of the romantic Julia. She never made the trip, however, as she discovered she was pregnant shortly before the troops embarked. It was probably for the better that she did not make the trip, as it went poorly and many men fell ill along the way. At Panama, a contractor failed to appear with transportation, and Quartermaster Grant was forced to buy mules to transport the troops across the isthmus. More than 150 men died in a cholera outbreak en route. The contingent did, however, ultimately reach San Francisco successfully.
During his time in the West, Grant repeatedly tried to raise the money to bring his wife and children–his second son, U.S. Grant, Jr., had been born shortly after he left–to California with him, failing each time. Throughout this period of Grant's life–and indeed throughout almost all of his life–Grant proved time and again that he was not an adept businessman. Shortly before leaving for California, Grant had journeyed to Washington to plead for the pardon of a $1,000 fine that had been levied him in punishment for the disappearance of a sum of $1,000 from a quartermaster unit Grant had commanded, and was thus responsible for. Grant visited his senators and congressmen and met with military officials, but left little or no impression on any of them and finally admitted failure in his endeavor. Later, while on the West Coast, he invested $1,500–his entire pay for his stint in California Coast–in the co-ownership of a small store in San Francisco. He never saw a penny from the investment and failed several times to recover a cent of his initial money. In another attempt at prosperity, Grant planted a potato crop on the banks of a Washington river, only to have the river flood and lose the entire crop.
It was perhaps Grant's posting to the remote Fort Humboldt on the California coast or his nasty superior there that finally broke him. Grant spent much of his California posting feeling miserable. Inexplicably, his wife showed little concern for his feelings during their separation, and the twice-yearly mail steamer sometimes arrived empty of letters for Grant. However, Grant deeply missed Julia and longed to meet the two-year-old namesake he had never seen. Grant had become lonely and despondent and set about to resign his commission and return home. Grant's father, who felt his son could never make it as a businessman, tried unsuccessfully to block his son's resignation from the Army, appealing to a senator and even to the Secretary of War. Grant returned to New York and waited there for word from Julia that he would be welcomed home. When a tepid response followed, he began the journey for St. Louis, arriving in October.