Thomas Chamberlain Thomas Davee Chamberlain ( April 29 , 1841 – August 12 , 1896 ) was an officer in the 20th Maine Volunteer Infantry Regiment during the American Civil War , the brother of Union general Joshua L . Chamberlain , the commanding officer of the 20th Maine Infantry . Early life . Thomas D . Chamberlain was born in Brewer , Maine , the youngest of five children . Young Tom grew up on the family farm in Brewer with his four older siblings : Joshua Lawrence ( born in 1828 ) , Horace Beriah ( 1834 ) , Sarah Brastow ( 1836 ) and John Calhoun ( 1838 ) . Their upbringing seems to have been strict and religious but also loving . Thomas was a mischievous and likable boy - his brother called him a " little rogue " - and , as the baby of the family , he was his mother ' s favorite . Thomas was the only son not to attend college . Whether this was due to lack of intelligence , application or inclination , is unknown . By his mid - teens Thomas was working as a clerk in a grocery store in Bangor . Civil War service . Chamberlain ' s great - grandfathers were soldiers in the American Revolutionary War and his grandfather had served during the War of 1812 . His father also had served during the abortive Aroostook War of 1839 . His brother Joshua was also in the army . In 1862 , Chamberlain joined the Union Army . His motives were mixed — personal , patriotic , and religious . He was soon placed in the newly formed 20th Maine Infantry along with his brother Joshua , who was made lieutenant colonel of the regiment . The 20th Maine regiment marched to the Battle of Antietam , but did not participate in the fighting . They fought at the Battle of Fredericksburg , suffering light casualties in the assaults on Marye ' s Heights , but they were forced to spend a miserable night on the freezing battlefield among the many wounded and dead from other regiments . They missed the Battle of Chancellorsville in May 1863 due to an outbreak of smallpox in their ranks , which kept them on guard duty in the rear . In June 1863 , Joshua was promoted to colonel of the regiment , after the promotion of its first colonel , Adelbert Ames , to brigade command . Thomas Chamberlain was involved in most of the other battles in which the 20th Maine fought , most notably the Battle of Gettysburg . The Battle of Gettysburg . During the defense of Little Round Top , the 20th Maine came under heavy attack from the Confederate 15th Alabama regiment , part of the division led by Maj . Gen . John Bell Hood , and after about 3 – 4 hours of fighting the 20th Maine completely ran out of ammunition . Chamberlain ' s brother Joshua recognized the dire circumstances and ordered his left wing to respond to the rebels by charging downhill with fixed bayonets , thus ending the Confederate attack on the hill . The 20th Maine and the 83rd Pennsylvania together captured over 400 soldiers from the attacking Confederate forces . Joshua was slightly wounded in the foot by a spent bullet . Thomas was unhurt , except for " several scratches " . As a result of their valiant defense of the hill , the Chamberlain brothers , Joshua Chamberlain especially , and the 20th Maine gained a great reputation and they were the subject of many publications and stories After Gettysburg . After Gettysburg , the major battles in which Thomas Chamberlain and the 20th Maine were involved were the Battle of Spotsylvania Court House and the Siege of Petersburg . At the Siege of Petersburg , the 20th Maine was in reserve , while Joshua ( against his better judgment ) led his Pennsylvania Bucktail brigade in a charge on a section of the Confederate defenses known as Rives ' s Salient . Turning to direct his troops , Joshua was struck by a minié ball , which entered just below his right hip , nicked his bladder and urethra , and stopped at his left hip . Such a devastating wound should have been fatal , and when he arrived at the field hospital , three miles behind the lines , his life was feared over . Thomas Chamberlain , back with his regiment , eventually heard the news . He and the surgeon of the 20th Maine , Dr . Abner O . Shaw , went to the hospital where Joshua was dying . As Thomas waited , Dr . Shaw , with Dr . Morris W . Townsend of the 44th New York , worked all night to try to save Joshua Chamberlain ' s life . Thirty - five years later , Joshua Chamberlain wrote that , after the surgeons had finished : " Tom stood over me like a brother , and such a one as he was . " Remarkably , Col . Chamberlain survived to enjoy his " on the spot " promotion to brigadier general , although he never returned to full fitness . A number of biographers of Joshua Chamberlain say that his life was saved through the activity of his brother , Thomas . Appomattox Campaign . After Petersburg , Thomas Chamberlain and the 20th Maine were involved in the Battle of Five Forks and the Battle of Appomattox Courthouse . At the end of the war , the 20th Maine marched from Appomattox , Virginia , on May 2 , reaching Washington , D . C . , on May 12 , where it was then finally mustered out of service on July 16 , 1865 . Postbellum . After the war , despite his distinguished military record , Chamberlain drifted from one job to another . He suffered from alcoholism as well as severe lung disease and heart disease . Death . Thomas D . Chamberlain died at age 55 in Bangor , Maine . He is buried at Castine , Maine . In Popular Media . Chamberlain was a character in Michael Shaara ' s Pulitzer Prize - winning historical novel , " The Killer Angels " . He was also portrayed in the movie based on that novel , " Gettysburg " , played by actor C . Thomas Howell , who repeated that role in the " Gods and Generals " prequel , based on the novel , " Gods and Generals " , written by Jeff Shaara , Michael Shaara ' s son .