At his father's death in 1637, Long inherited the bulk of his Wiltshire estates, including the manor of Draycot Cerne.
His friend, historian John Aubrey, wrote: "When there was a Cabal of Witches detected at Malmesbury they were examined by Sir James Long and committed by him to Salisbury Gaole.
He married secondly, c.1640, Dorothy, daughter of Sir Edward Leech (MP) (or Leche) of Shipley Hall, Derbyshire and Drury Lane, London.
Strangeways; the father by high unkindnesse and folly, the son by hard usage of his wife, who has betaken herselfe wholy to her father's (Strangeways) house, and by the foolish losse of £15,000 in one year at play, in so much that hee dare not stirr out of his house in the country"[3] James appears to have continued his errant ways, when a further incident occurred in 1683.
The plaintiff, Mary Keightley, was trying to recover a debt from Mr. James Long, and in consequence of the suit the Court sanctioned the sequestration of his estates.
Three men, armed with a commission from the Court, were sent to Athelhampton, and their request for information about Long from the villagers met with an eager response.
Susanna's brother later asserted that his sister was "soe affrighted" by the deportment of the men that she languished, and in a short time died.
James's sister Anna wrote approvingly to their mother that Mary had "brought my brother of his drinking in a great measure and to love home".