John was the son of James B. Finley Page and his wife Mary Lucinda Thorpe. Mary died when John was just three weeks old so he was adopted by Orson Bennett Adams and his wife Susan Smith Adams, a childless couple. Orson and Susan accompanied the Mormon Battalion to New Mexico so John crossed the plains with Susan's parents, Priddy and Sarah Smith Meeks. Orson and Susan arrived in Salt Lake with the Mormon Battalion Sick Detachment. The family was then called to help settle Little Salt Lake (now Parowan) in Iron County. In the 1850 Utah census Orson is spelled "Arsen"; John is listed as "John S. Adams, age seven.