Joseph D. Baker was born around 1839 in Findley, Pennsylvania, to John Baker and Susan Walker. His father was a farmer who owned $790 of real estate by 1850. Baker grew up and attended school in Findley, and his father died in 1857. By 1860, he was working as a music teacher in Findley.
He enlisted in the Union army on September 23, 1861, and he mustered in as a private in Company F of the 57th Pennsylvania Infantry on October 30. According to his service records, he was 5 feet, 6 inches tall, with dark hair and blue eyes. He wrote a poem in October 1861 declared that he was “marching with the brave…Our country to maintain.” He also denounced the “curse of slavery.” The regiment took part in the Battle of Seven Pines, the Seven Days’ Battles, the Second Battle of Bull Run, the Battle of Fredericksburg, the Battle of Chancellorsville, and the Battle of Gettysburg.
After the Battle of Williamsburg in May 1862, he declared that “I now know by experience something of the ‘Horrors of war.’ I have seen the battle-field and met the enemy twice, and believe me, it is as tough a place as words can express. I do not wish to see such a sight as Williamsburg field again.” He remained staunchly loyal to the Union. In July 1862, he gave a Confederate woman “the contents of my haversack and told her to teacher her children…to be loyal to the government of the U.S.” He denounced “the Copperhead gang,” writing that their “every howl is only strengthening the hand of the devilish foe in our front.”
Confederate forces captured him at Gettysburg on July 2, 1863, and he spent the ensuing months imprisoned at Belle Isle and Andersonville. He died in Andersonville on May 12, 1864.