The most detailed account of Pitman's final fate in the war came from Robert G. Carter.
In November 1862, Pitman was captured near Warrenton Junction on the march toward Fredericksburg, Virginia, during the weeks prior to the Battle of Fredericksburg.
He had fallen behind the group because his feet had blistered and swollen due to the tightness of "a pair of thin, high-heeled and narrow soled boots" he had purchased.
One of his comrades temporarily stayed behind to care for him but later decided to move on with the rest of the camp for fear of disciplinary consequences of falling out without authority.
He was urged to move on, but without much success.
Pitman's last words to his comrade were, "I will be in camp by night, good by."
His fellow soldiers never saw him again and considered him missing.
Shortly after he was left, a band of Confederate guerrillas under Colonel John S. Mosby captured the weary and defenseless soldier without a struggle.
The inscription on his tombstone differs slightly from Carter's account, stating he was captured by J. E. B. Stuart's cavalry instead.

After Pitman's capture, he was marched to Richmond in a weak physical state.
He was imprisoned in the Confederate Libby Prison and Belle Isle, which were notoriously harsh prisons.
Pitman's letters home described his place of incarceration as the "Pen" where "the filthy meat [was] thrown to them as if they were dogs".
The condition of his incarceration including the shortage of food, lack of sanitation, overcrowding and his physical weakness made him susceptible to virulent diseases present in the Confederate prisons.
Carter described how the prisons "wore out the brave spirit".
During a prisoner exchange, Pitman was released by the Confederate Army at City Point, Virginia, on December 12, 1862, and then sent to Camp Parole, Annapolis.
Suffering from complications due to the conditions of his imprisonment, he contracted "lung fever", which was perhaps pneumonia.
Carter wrote later how his friend had "linger[ed] feebly a few weeks, like the flickering of an expiring flame, then quietly pass[ed] away to an eternal life".
Pitman died at Camp Parole on February 27, 1863, just weeks short of his eighteenth birthday.
According to historians Anita Manning and Justin Vance, Pitman "has the unfortunate distinction of being the only known Hawaiian or Pacific Islander to die as a prisoner of war in the Civil War".

Considering him missing, Pitman's regiment did not discover his final fate until news of his funeral at Roxbury was received in the spring of the following year.
His remains were returned to his family in Massachusetts after his death in Camp Parole.
Benjamin Pitman, his father, had him buried in a family plot in Mount Auburn Cemetery.
On one side of the Pitman family grave marker was placed the inscription:
Timothy Henry Pitman
Born at Hilo, Hawaii
Mar. 18, 1845
Died at Camp Parole
Annapolis, MD, Feb'y 27, 1863
Aged 17 years 11 mos.
9 days
A member of Co. H, 22nd Regiment
Mass. Vols.,
was with his Regiment in the
battles of South Mountain, Antietam and 
Sharpsburg.
Was taken prisoner by Stuart's
cavalry on the march to Fredricksburg;
Imprisoned in Libby Prison, paroled and
sent to Camp Parole, Annapolis, and died in
camp of pneumonia.
The most detailed account of Pitman's final fate in the war came from Robert G. Carter. In November 1862, Pitman was captured near Warrenton Junction on the march toward Fredericksburg, Virginia, during the weeks prior to the Battle of Fredericksburg. He had fallen behind the group because his feet had blistered and swollen due to the tightness of "a pair of thin, high-heeled and narrow soled boots" he had purchased. One of his comrades temporarily stayed behind to care for him but later decided to move on with the rest of the camp for fear of disciplinary consequences of falling out without authority. He was urged to move on, but without much success. Pitman's last words to his comrade were, "I will be in camp by night, good by." His fellow soldiers never saw him again and considered him missing. Shortly after he was left, a band of Confederate guerrillas under Colonel John S. Mosby captured the weary and defenseless soldier without a struggle. The inscription on his tombstone differs slightly from Carter's account, stating he was captured by J. E. B. Stuart's cavalry instead.
After Pitman's capture, he was marched to Richmond in a weak physical state. He was imprisoned in the Confederate Libby Prison and Belle Isle, which were notoriously harsh prisons. Pitman's letters home described his place of incarceration as the "Pen" where "the filthy meat [was] thrown to them as if they were dogs". The condition of his incarceration including the shortage of food, lack of sanitation, overcrowding and his physical weakness made him susceptible to virulent diseases present in the Confederate prisons. Carter described how the prisons "wore out the brave spirit". During a prisoner exchange, Pitman was released by the Confederate Army at City Point, Virginia, on December 12, 1862, and then sent to Camp Parole, Annapolis. Suffering from complications due to the conditions of his imprisonment, he contracted "lung fever", which was perhaps pneumonia. Carter wrote later how his friend had "linger[ed] feebly a few weeks, like the flickering of an expiring flame, then quietly pass[ed] away to an eternal life". Pitman died at Camp Parole on February 27, 1863, just weeks short of his eighteenth birthday. According to historians Anita Manning and Justin Vance, Pitman "has the unfortunate distinction of being the only known Hawaiian or Pacific Islander to die as a prisoner of war in the Civil War".
Considering him missing, Pitman's regiment did not discover his final fate until news of his funeral at Roxbury was received in the spring of the following year. His remains were returned to his family in Massachusetts after his death in Camp Parole. Benjamin Pitman, his father, had him buried in a family plot in Mount Auburn Cemetery. On one side of the Pitman family grave marker was placed the inscription:
Timothy Henry Pitman
Born at Hilo, Hawaii
Mar. 18, 1845
Died at Camp Parole
Annapolis, MD, Feb'y 27, 1863
Aged 17 years 11 mos. 9 days
A member of Co. H, 22nd Regiment
Mass. Vols., was with his Regiment in the
battles of South Mountain, Antietam and 
Sharpsburg. Was taken prisoner by Stuart's
cavalry on the march to Fredricksburg;
Imprisoned in Libby Prison, paroled and
sent to Camp Parole, Annapolis, and died in
camp of pneumonia.
Henry Hoʻolulu Pitman