William was born in Hobkirk, Roxburgh, Scotland. He was baptized 11 October 1801. Prior to 1826 he married Mary Ann Dodds, daughter of John and Elizabeth Dodds. (Mary Ann is a sister to Ann Dodds, wife of Andrew Turnbull). William became a U.S. citizen 29 January 1828. He served as Trustee of the Presbyterian Church of Oxbow, New York. In the 1873-1874 County Business Gazetteer, William is listed as a farmer with 369 acres.

The family lived in Rossie on a farm, which they cleared of timber from a dense wilderness. It was located midway between Wegatchie and Oxbow on the Oswegatchie River upon the opposite bank from the highway. Later the family located on a farm just outside the village of Rossie. William died in 1872 at the age of 71 and Mary Ann died in 1891 at the age of 88. Both died in Rossie, NY. No graves have been found for either of them. Death records list them buried in the old Oxbow Cemetery but they do not appear in the cemetery burial records. The farm was sold to Jerome O'Brien about 1891 when William's wife Mary Ann died .

Died in Rossie, N.Y. May 4, 1872, Mr. Wm. Turnbull in the 71st year of his age.

Mr. Turnbull was a native of Roxburghshire, Scotland, he emigrated to this country in 1820 and settled in Rossie, where he lived for upwards of 50 years, beloved and respected by all who knew him.

William and Mary Ann had ten children:

1) Thomas

2) Betsy Elizabeth

3) Sarah

4) John. C.

5) William

6) Michael Henry

7) James C.

8) Mary Ann

9) Andrew

10) George W.

1) Thomas married Almeda Countryman(A sister to his cousin Thomas Peronious Turnbull's wife, Julia Countryman) and had twelve children, including five who died at an early age. Thomas died in 1881 and was buried in Rossie, NY.

2) Betsy Elizabeth did not marry and died in 1911 in Gouveneur, NY.

3) Sarah married Wallace McKean in 1861 and had one child. She died in 1863 in Gouveneur, NY.

4) John C. married Grace Kane in 1858 and had one child. He died in 1862 at the age of 28 from an illness contracted soon after joining the Civil War. He was buried in Oxbow, NY.

5) William married Nancy Mc Mullen and had five children. He died in 1908 and was buried in Rossie, NY.

6) Michael Henry married Betsy Dority in 1864 and had four children. His son John Henry left home for Utah at an early age, perhaps seeking his fortune in mining at Park City, Utah. Michael H. died in 1903 in Rossie, NY.

(Many men went to Utah from Rossie to stake mine claims beginning in 1882; so many in fact that there is a hill in Park City, Utah called "Rossie Hill").

7) James C. married Emeline Bellinger and had two children. James learned the trade of blacksmith and wheelwright and manufactured carriages, wagons and sleighs for many years. He died in 1916 and was buried in Gouveneur, NY.

8) Mary Ann married Wallace McKean in 1866. (Her sister Sarah's widower)and had two children. She died in 1925 in Gouveneur, NY.

9) Andrew, born in 1845, appears on the 1850 census as being five years old. He did not appear on the 1860 census. No other information has been found on him and he is believed to have died at an early age since he is not mentioned in his father's 1872 will;

10) George W. never married and died in 1930 in Canton, NY.

In the early years when the town of Rossie held their observation of Robert Burns' birthday, known as "Burns Festival", the haggis was prepared by the wife of the pioneer, William Turnbull. These festivals would serve 200 or more people.