John was the third child of Thomas Foster Rhoads and Elizabeth Forster Rhoads. Born on October 5, 1818 in Muhlenburg County, Kentucky. Moved as a young child to Vincennes, Indiana where the family farm was destroyed by Native Americans. Settled in Edgar County, Illinois, and then in Ray County, Missouri.

The Rhoads family came to California in 1846 under the orders of Brigham Young. Separating at the Hastings' cut-off from the Donner party and following the old route the Rhoads family escaped the disasters that befell the Donners. He was captain of the first and fourth relief parties, and among the heroic services rendered one grateful survivor, Naomi L. Pike for over forty miles he carried her upon his shoulders, carefully wrapped up in a blanket. Early in 1847 he moved to Sonoma County with his wife and children, but in the fall of that year he bought land on the Cosumnes, known as lot five of the Sheldon estate. With the discovery of gold in 1848 his farming plans were laid aside for a time, and he went to mining in Rhoads Diggings, near Folsom. Later in the year when the gold fever had somewhat chilled, he moved his family to his ranch on the Cosumnes, and engaged in general farming and stock-raising.

John served on the jury for Lewis Keseberg's cannibalism trial following the Donner tragedy. Elected as a California State Legislator (Union Party) in 1863. He was a school trustee of the Rhoads District for twenty years. The Rhoads Schoolhouse now stands in Elk Grove Regional Park as a museum and living history center.

Married Matilta Fannin in 1838 in Edgar County, Illinois. Parents of Thomas F. Rhoads, Mary Elizabeth Rhoads, George Washington Rhoads, Matthew Miller Rhoads, Daniel Rhoads, Andrew Jackson Rhoads, James K Polk Rhoads, and William B. Rhoads.

Married Mary Murray in August 1852 in Sloughhouse, California. Parents of Jonathan K. Rhoads, John M. Rhoads, Francis J. Rhoads, Michael M. Rhoads, Daniel C. Rhoads, Emmett Rhoads, and Rufus Henry Rhoads
John Pierce Rhoads died December 20, 1866 in Sloughhouse, California