Samuel Campbell was born around 1831 in Florence, Pennsylvania, to Josiah and Rosanna Campbell. His father was a carpenter who owned $300 of real estate. He grew up and attended school in Beaver County, Pennsylvania, and by 1850, he was working as a carpenter.
He married Jane Vance around 1855, and they had at least five children: William, born around 1856; Samuel, born around 1860; Anna, born around 1865; Thomas, born around 1868; and Joseph, born around 1878. They lived in Hanover, Pennsylvania, and Campbell worked as a farmer. By 1860, they owned $3,000 of real estate and $1,000 of personal property.
On August 22, 1862, he received a commission as a 2nd lieutenant in Company H of the 140th Pennsylvania Infantry. The regiment took part in the Battle of Chancellorsville, the Battle of Gettysburg, the Overland Campaign, and the siege of Petersburg. He was promoted to captain on November 1, 1862. He was wounded on July 2, 1863, in the Battle of Gettysburg, and again on June 17, 1864, in the siege of Petersburg. He mustered out on September 18, 1864.
Campbell returned to Hanover after the war and resumed his work as a farmer. By 1870, he owned $10,600 of real estate and $2,854 of personal property. He joined the Grand Army of the Republic after the war. He died in Pennsylvania on March 8, 1887.