Question: how many times was ben cartwright married on bonanza
Answer: He had three sons , each by a different wife : the eldest was the urbane architect Adam Cartwright ( Pernell Roberts ) who built the ranch house ; the second was the warm and lovable giant Eric `` Hoss '' Cartwright ( Dan Blocker ) ; and the youngest was the hotheaded and impetuous Joseph or `` Little Joe '' ( Michael Landon ) .