This is a new story to me, but you definitely have my interest, provided this is a Civil War story. You see, murders of entire or nearly entire families was rare during the Civil War in Missouri.
I'm having trouble finding this family in the 1860 MO Census. The index of this census prepared by the LDS church shows four Allison or Alison households all in Osage Township of north-central Camden County (Benjamin, Catherine, John, and William). Could one of these be your Hugh Allison family? Are any of these related to Hugh? When did Hugh Allison settle in Camden County?