A trademark of the dynasty over its 140-plus years has been the remarkable unity it has maintained, despite major divisions that developed in the late 1970s, and unlike other rich families such as the DuPonts and the Mellons. A primary reason has been the lifelong efforts of "Junior" to not only cleanse the name from the opprobrium stemming from the ruthless practices of Standard Oil, but his tireless efforts to forge family unity even as he allowed his five sons to operate independently. This was partly achieved by regular brothers and family meetings, but it was also because of the high value placed on family unity by first Nelson and John 3rd, and later especially with David.