Sometimes a cemetery can tell you of this, depending upon what period, of course. Back in the 70's my sister and I were researching the family of our grandmother, Harriet Stuart Robinson. She'd died when Dad was only 7, so we had little but a few photos, and a Bible entry of her marriage (still haven't come up with her birth date!) Long before Ancestry.com provided census records, my sister and I made a trip to Cooperstown NY. There in the big cemetery were the stones of her mother and father, and another one headed Jesus' Lambs: Marion and Nellie, of whom we had no knowledge at all, had died before Hattie was a gleam in her father's eye! Cemetery records said they'd died of diphtheria. No wonder Harriet looks so troubled as a child! Her mother must have kept her wrapped in cotton wool after losing 2, and never having any others. But of course, they had died in 1861, when there were more records. But before that?? Jean