Notes:

They came to Pennsylvania (from Ireland?)
Differing sources us Douglas and Douglass. 'Curly Billy's gravemarker has the double ss.

(Research):There is contradictory material on Barnabus and his family.
This is just one version:

Indiana Co., Pennsylvania, Her People, Past and Present, J.T. Stewart, 1913, pub. by J.H. Beers. PP 1578-1579

" JONATHAN DOUGLASS
[grandfather] BARNABAS DOUGLASS was a native of Dublin, Ireland, whose wife was also born in that country. Upon coming to America, they settled in Philadelphia, later moving to Cambria county, Pa., where they remained about eighteen years. At the end of that time the family came to Indiana county, purchasing a large tract of land in Green township near the Cambria county line, where Barnabas Douglass continued to live and farm until his death. He had a family of five children, three sons and two daughters, all of whom are now deceased."

Family/Spouse: Sarah Keech. Sarah was born in 1778; died in 1844; was buried in Cherry Tree, Pennsylvania, USA. [Group Sheet] [Family Chart]

1. Many Children Douglas
2. John B. Douglass was born in 1800; and died.
3. Barnabas Douglas was born in 1803; died on 28 Nov 1875.
4. Margaret Douglas was born in 1806 in Pennsylvania, USA; died on 28 Mar 1865 in Indiana County, Pennsylvania, USA; was buried in Douglass Cemetery, Indiana County, Pennsylvania, USA.
5. William George "Curly Billy" Douglas was born in 1808 in Cambria County, Pennsylvania, USA; died on 20 Feb 1886 in Indiana County, Pennsylvania, USA; was buried in Douglass Cemetery, Indiana County, Pennsylvania, USA.