Jupeter was the son of Peter Wells of Ashfield, Massachusetts. He is described in Ashfield vital records as being "colored." He married a woman named Sally and the couple had at least seven children- Sukey, born in 1803, Joseph, born in 1805-1807, Jupeter, Jr., born in 1806, and an unnamed child who was born in 1817 and died in 1819. The 1820 census for Ashfield lists eight people in the "free colored" column, which accounts for the children mentioned above, plus three girls under the age of 14.
Sally, also described in Ashfield vital records as being a woman of "color," died in February of 1821, of "dropsy in brest." She was 37 or 38 years old.