Meigs' father was assigned to a number of military posts while John was young, and the family moved often. After his birth, his father was assigned to Fort Wayne near modern-day Detroit, Michigan. He was largely taught at home in these formative years. He began speaking at an early age, learned the alphabet while still very young, and was reading and writing by the age of four. In 1849, the Meigs family returned to the District of Columbia, but in October 1850 they moved to Rouses Point, New York, where John's father was engaged in building Fort Montgomery. John had a violent temper and often bullied his siblings, behaviors which deeply concerned his parents.