The men closed their law office when the Civil War began, and all four would serve as generals in the Union Army.

He became colonel of the 52nd Ohio Infantry on July 15, 1862, and commanded a brigade under his old law partner Sherman in the Army of the Cumberland.

He was selected by Sherman to lead the assault on Kennesaw Mountain on June 27, 1864, and took his brigade directly up to the Confederate works.

Just before the attack, he calmly recited to his men the stanza from Thomas Macaulay's poem of "Horatius" beginning "Then how may man die better than facing fearful odds?"

He had reached the top of the enemy's works, and was encouraging his men to follow him, when he was mortally wounded by a rifle shot to his right lung.