When General Johnston was wounded at Seven Pines, and General Lee took command, one of the first inquiries of General Lee was: "Where is Dr. Guild? Tell him to report to me at once." It was on the battle field of Seven Pines that Dr. Guild was made medical director and chief surgeon of the army of Northern Virginia, which position he held to the close of the war. This position placed him on General Lee's staff, and from that time till the close of the long and bloody tragedy, Dr. Guild sustained the closest personal relationship with the greatest southern chieftain.
When General Lee invaded Pennsylvania, he was one day riding through a town at the head of his troops, the people of which town gave every demonstration of hostility to the Confederates. From the windows and balconies of the homes, the women waved flags and accompanied their demonstrations with hissing and jeering. From all this the delicate and sensitive nature of Lee shrank, and, turning to one of his aides, he said: "Bring Drs. Guild and Breckenridge to the front." Two more graceful and commanding personages were not in the army, and when they came galloping up, General Lee quietly placed himself between them, and the three rode abreast. With characteristic modesty, General Lee later explained his reason for summoning the two physicians to the front, by saying he felt sure "the ladies would not ridicule two such handsome men and splendid horsemen as the two distinguished physicians."
The war being over, Dr. Guild went to Mobile, and though still practically a young man, he was wrecked in health by the strain and exposure incident to the long war. His energetic spirit strove with his disabled body, and he entertained the hope that by carefully husbanding his remaining strength he might be able to recuperate. His plan was to begin life over again by entering on private practice in the Gulf city. But his valuable services were soon summoned to another sphere, for he was made quarantine inspector of Mobile during a scourge of yellow fever, and by his skill and diligence stayed its ravages. In 1869, Dr. Guild removed to San Francisco with the hope of resuscitation in an equable climate, but he did not long survive his removal, for on July 4, 1870, he died of rheumatism of the heart in the little town of Marysville, California.