Arabella Durlin/g was of Dutch descent. Her parents were David Durlin/Dorland and Ann Pierce. Per THE DORLAND ENIGMA SOLVED by B. Barth, and Ancestry.com, the ancestry is:
Gen 1. Lammert Janse Dorland (b ~1648 - d ~ 1724) + Harmtje Jans or Harmtje Pieters - married about 1671 - Lammert arrived in colonies (NY) on 16 Apr 1663 on the Bonte Koe. He settled in Brooklyn, later he is listed on the 1708 Staten Island census.
Gen 2.Gerrit Dorland (b ~ 1674 - d ~ 1632) + Marytje (unknown surname) married ~ 1694
Gen 3. Jan Dorland (b 1702- d bef 1731) + Catherine Davis (b 1706) married about 1724. They lived in Brooklyn
Gen 4. Gerrit Dorland (bap 7 Nov 1730 New Utrect - d aft 1810). He appeared on the 1800 census(wife deceased) & on the 1810 census with son Lorentz in Northumberland Co., PA.
Gen 5. David Dorland, Sr. (b ~ 1756 - d 1810) married abt 1777, wife is unknown.
Gen 6. David Durlin/Dorland Jr. (b 1790 - d 9 Mar 1841 Fredonia, NY) He was a shoemaker. He married Ann Pierce in abt 1816 in Penn Yan, NY.
Ann Pierce (b 6 Dec 1799 - d 17 Apr 1863 Fredonia, NY). Her parents were Abner Pierce (b 23 Jan 1769 Freetown, MA - d 1830 Milo, NY) He was a blacksmith & tavern keeper. He was the son of Abraham Pierce and Priscilla Reed. He married Lorana Spooner in 1788, New Bedford, MA.
As for Orrin Morrison, he was NOT born in Scotland. He was born in Washington County, NY, probably in Hartford where his father inherited a farm (as were all of his siblings). The family moved to Forestville, Chautauqua County soon after Orrin's birth. Orrin is of Scottish descent. His great-grandfather was born in Scotland, immigrated to North Ireland as a young child and then to the colonies in 1726. Orrin's mother's maiden name was Patterson.
As for Frank Sprague Morrison, his middle name is likely for a family friend's surname or a church pastor's surname...there are no Spragues in this branch of the Morrison family but Spragues did live in the areas that the Morrisons lived in (MA and NY). These Morrisons frequently used this pattern for their children's middle names.
I understand that Wendy Lawrence is now deceased and I want to thank her for all the work she did on her family tree. I found it helpful for Frank Sprague Morrison's branch of the family.