Prescott S. Bush Jr., the brother of one president and uncle of another, and a retired insurance executive who tried but never made it far in the family business — politics — died Wednesday after a long illness. He was 87. Mr. Bush’s death was confirmed by Tracey Bergonzi, a spokeswoman at Keohane Funeral Home in Hingham, Mass., a town where Mr. Bush had lived for several years. The cause of death was unclear. Besides being the uncle of one president, George W. Bush, and elder brother of another, George Bush, he was the son of a wealthy senator, Prescott...