John P. Parker started life in slavery and rose to the role of innovator and businessman. The son of a black slave mother and a white father, he was born at Norfolk, Virginia, and was sold into slavery at the age of eight. Sent to Mobile, Alabama, he was purchased by a physician in 1843. While under the doctor's ownership, Parker learned to read and write. He was also apprenticed as a molder at an iron foundry. Twice his high productivity was a source of irritation to his coworkers, at the foundry in Mobile and at a foundry in New Orleans. At a third foundry, Parker stayed for two years and accumulated $1,800 in savings, the amount he needed to purchase his freedom.

In 1845, a free man, he went first to Indiana, where he was involved in abolitionist activities and the Underground Railroad, which rescued people from slavery in the South. Parker married Miranda Boulden of Cincinnati in 1848. Two years later, Parker and his family moved to Ripley, Ohio, where he again became involved in abolitionism, aiding in the freeing of over a thousand slaves.

He established a small foundry in Ripley, the Ripley Foundry and Machine Company, in 1854 to manufacture castings. In 1863 he became a recruiter for the 27th Regiment of the United States Army, a black unit, to serve in the Civil War. His foundry also made castings for the war effort.

In 1884, Parker obtained a patent for a screw for tobacco presses and a year later patented a type of harrow called the Parker Pulverizer. Both items were produced in his foundry. These patents were issued at a time when patents were rarely awarded to black inventors. Parker's foundry remained in operation until 1918, well after his death.