In some families, the person who makes everything possible is the one who stands still. Barack Obama's grandmother Madelyn Dunham, who died on Nov. 3 at 86, was married to a man fueled by bluster and possibility, who moved the family five times before settling in Hawaii. Her daughter inherited that restlessness, marrying an African, then an Indonesian and building a life in Jakarta. And then there was the grandson who captured a nation's imagination.
But standing at the center of these questing characters was Dunham, a Maypole in a business suit and sensible shoes. When her husband went to war,...