My husband is a great great-grandson of Nathan and Mahulda Smith. I don't think this is the Josiah Smith line you are looking for.
Mahulda's brother, according to census records was born around 1834. He was married to a woman named Leann.
They did have a son John H. born 1860 in Pendleton Co. West Virginia. John was married to Bettie A. Their children were:
Bertie V. born 1886
Zella D. born 1889
Virgie L. born 1891
Maggie E. born 1894
Irma W. born 1896
Joe P. born 1904