Almost everyone I spoke to for this story mentioned the sugar cube missions, for they reveal much about how we teach American history, sweetening depredations until the bitterness is gone. Of course, there is a limit to how much depravity a 9-year-old can grasp. Which may be the point. Consigning the history of California Indians to the fourth grade is a convenient means of forgetting it. And yet the same state that now teaches the Armenian genocide and, earlier this year, amended history textbooks after complaints from some South Asians is hesitant to look deeply into its own history.