John D. Beach was born around 1841 in Litchfield County, Connecticut, to Benjamin Burroughs Beach and Mary Sturdevant. His father was a painter. The family lived in New Milford, Connecticut, until the 1850s, when they moved to LaSalle County, Illinois. His father probably died in the 1850s. By 1860, Beach was living in Deer Park, Illinois, and working as a farm laborer.
He enlisted in the Union army on August 23, 1861, and he mustered in as a private in Company G of the 55th Illinois Infantry on October 31. According to his service records, he was 5 feet, 6½ inches tall, with light hair and blue eyes. The regiment took part in the Battle of Shiloh, the siege of Corinth, the Vicksburg campaign, the Atlanta campaign, the March to the Sea, and the Carolinas campaign. He reenlisted in 1864 against the wishes of his father, who believed that “this war will never end as long as Old Abe is President.” He contracted smallpox during the winter of 1864-65, but he eventually recovered. He eventually earned a promotion to corporal, and he mustered out on August 14, 1865.
He married America Ann Woods on July 17, 1867, and they had at least three children: Linne, born around 1875; Jessie, born around 1877; and Charles, born around 1881. They moved to Medicine Creek, Nebraska, in the late 1870s, and he worked as a barber there. He applied for a federal pension in September 1878 and eventually secured one. The family moved to Araphahoe, Nebraska, in the 1880s and then to Santa Ana, California, in the 1890s. Beach worked as a “capitalist” in Santa Ana. They moved to Long Beach California, in the early 1900s. He died of “natural causes” in Los Angeles, California, on October 4, 1922.