I am not a direct ancestor of John Kappus (Cavis), however, my husband and children are. I am trying to compile a family tree for my kids and came across your post. Like the poster above me, they too are great great grandchildren of Earl Cavis. The information I have (that links my children to John) is as follows:
John Kappus (Cavis) married Jane Dunbar. They had a son Fredrick Cavis. Fredick married Martha Gray. They had a son Frank Cavis. Frank married Mary Myrtle Sawin. They had a son, Earl Cavis. Earl married Opal Brown, and had a son, Allan Cavis. Allan married Lucille Martinez, and they had a son, Buckley Cavis. Buckley married Rebecca Taylor, and they had a son, Nicholas Cavis. Nick is my spouse (I am Emily Warren) and we have two children, Benjamin and Liberty Cavis.
Liberty is probably the youngest ancestor of John Kappus (right now, anyway) as she is about 3 months old :)
I have some additional information on dates of birth/death/marriage and additional children of the people I listed.
I'd also love to hear if you find anything that goes back further than John Kauups- as that seems to be my road-block.