[47] Garfield's troops received word of the battle and advanced quickly, joining the rest of the army on the second day to drive the Confederates back across the field and into retreat.[48] The action, later known as the Battle of Shiloh, was the bloodiest of the war to date; Garfield was exposed to fire for much of the day, but emerged uninjured.[48] Major General Henry W. Halleck, Grant's superior, took charge of the combined armies and advanced ponderously toward Corinth; when they arrived, the Confederates had fled.[49]
That summer, Garfield suffered from jaundice and significant weight loss.[b][51] He was forced to return home, where his wife nursed him back to health.[51] While he was home, Garfield's friends worked to gain him the Republican nomination for Congress, but he refused to campaign with the delegates.[52] He returned to military duty that autumn and went to Washington to await his next assignment.[53] During this period of idleness, a rumor of an extramarital affair caused friction in the Garfields' marriage until Lucretia eventually chose to overlook it.[54] Garfield repeatedly received tentative assignments that were quickly withdrawn, to his frustration.