When I sing it I replace the first two lines, the first (my mammy was a squaw) being objectionable in America and the second (pappy hailed from Timbuctoo) making no sense. I sing:

I was born in Arkansas, where my mammy met my pa.
Pappy hailed from up north in Missou'.

A couple corrections from the above: the Corries version has lyrics as follows.

It had a cedar shingle roof...

... he hauled me on his knee.....