Joshua Lawrence Chamberlain began as a scholar and teacher, returning to Bowdoin College after theological study to teach languages and rhetoric. In 1862 he entered Union service as lieutenant colonel of the Twentieth Maine Infantry. Without professional military training, he learned under Colonel Adelbert Ames and through his own study. The regiment endured the failed assault at Fredericksburg before Chamberlain succeeded Ames in command.

At Gettysburg on July 2, 1863, the Twentieth Maine defended the Union army's extreme left on Little Round Top. After repeated Confederate attacks, its counterattack with bayonets helped secure the position. The precise initiation and execution of that charge remain debated, but Chamberlain's leadership brought national recognition and the Medal of Honor. His service extended beyond Gettysburg.

Promoted to brigade command, Chamberlain suffered a severe wound at Petersburg in June 1864 that initially appeared fatal. He survived and returned to the army, taking part in the final campaign against Robert E. Lee. In April 1865 he supervised the ceremonial surrender of Confederate infantry weapons at Appomattox. This was distinct from Grant's acceptance of Lee's surrender terms on April 9. Chamberlain's later account emphasized a salute to the defeated soldiers, contributing to the ceremony's place in remembrance of the war.

He served four one-year terms as governor of Maine from 1867 to 1871, then became Bowdoin's president, holding office until 1883. His educational initiatives included efforts to broaden the curriculum, while compulsory military drill provoked resistance. He also helped maintain order during Maine's disputed election crisis in 1880. Later business ventures and public appointments accompanied his writing and speaking about the war. The Passing of the Armies, published after his death, presented his account of the Appomattox campaign. His career combined command, government, and education.