Promoted to captain on August 5, 1853, Grant was assigned to command Company F, 4th Infantry, at the newly constructed Fort Humboldt in California. Grant arrived at Fort Humboldt on January 5, 1854, commanded by Lieutenant Colonel Robert C. Buchanan, a martinet officer, with whom Grant had earlier crossed paths at Jefferson Barracks. Separated from his wife and family, Grant began to drink. Colonel Buchanan reprimanded Grant for one drinking episode and told Grant to "resign or reform." Grant told Buchanan he would "resign if I don't reform." On Sunday, Grant was found influenced by alcohol, but not incapacitated, at his company's paytable. Keeping his pledge to Buchanan, Grant resigned, effective July 31, 1854. Buchanan endorsed Grant's letter of resignation but did not submit any report that verified the incident. Grant did not face court-martial, and the War Department said: "Nothing stands against his good name." Grant said years later, "the vice of intemperance (drunkenness) had not a little to do with my decision to resign." With no means of support, Grant returned to St. Louis and reunited with his family, uncertain about his future.