It had been reported to General Palmer that the defeat of the Federal troops might have been avoided had the officers been on duty.  An investigation was ordered and Captain Conwell was asked for his permit to be absent.  He had simply his pass through the lines, a vastly different thing he found from an authorized permit of absence.  The investigation dragged its slow course along, as all such things, encumbered by red tape, do.  Disgusted and humiliated by being kept a prisoner for months when the country needed every arm in its defense, by having such a mountain made of the veriest molehill built of a kind act and boyish inexperience, he refused to put in a defense at the investigation and let it go as it would.  Setting the Court of Inquiry more against him, a former Commander, General Foster, espoused his cause too hotly and wrote to General McPherson for an appointment for a “boy who is as brave as an old man.”  The Court of Inquiry, made up of local officers, most of them jealous of his popularity, resented this outside interference and the verdict was against him.  But others higher in authority took up the matter and Captain Conwell was ordered to Washington.  The President reversed the order of the Court.  He was appointed Lieutenant-Colonel, detailed for service on General McPherson’s staff and ordered West.  General Butler, under whose command Captain Conwell served, afterward made a generous acknowledgment of the injustice of the findings and expressed in warm words his admiration of Captain Conwell, and the State Legislature of Massachusetts gave him a certificate for faithful and patriotic services in that campaign.

Nevertheless, it was an experience that sorely embittered his soul.  Intentionally he had done nothing wrong, yet he had been humiliated and made to eat the bitter fruits of the envy and jealousy of others.  It saddened but did not defeat him.  His heart was too big, his nature too generous.  He could forgive them freely, could do them a kindness the very first opportunity, but that did not take away the pain at his heart.  One may forgive a person who burns him, even if intentionally, but that does not stop the burn from smarting.

Saddened, and with the futility of ambition keenly brought home to him, he joined General McPherson, and in the battle of Kenesaw Mountain he received a serious wound.  He had stationed a lookout to watch the Confederate fire while he directed the work of two batteries.  It was the duty of the lookout to keep Colonel Conwell and his gunners posted as to whether the enemy fired shot or shell, easily to be told by watching the little trail of smoke that followed the discharge.  If a shot were sent, they paid no attention to it for it did little damage, but if it were a shell it was deemed necessary to seek protection.

Colonel Conwell was leaning on the wheel of one of the cannon when there was a discharge from the guns of the enemy.  The lookout yelled, “Shot.”  But it was a fatal shell that came careening and screaming toward them, and before Conwell or his men could leap into the bomb-proof embankment, it struck the hub of the very wheel against which he leaned, and burst.