On Thomas Devane's tombstone, he is referred to as "Jr". He was however the third Thomas Devane and his son, Thomas was referred to as the IV. He was also called "Baby Tom".
The spelling of Devane changed to DeVane , when researching check both spellings.
Thomas Devane married Gregg Marie/Margaret Bloodworth(1764-1791). See Deed Bk H pg. 193 & DB H pg. 206 New Hanover Co., NC. She is a daughter of Timothy(1736-1814) & Priscilla Jones Bloodworth.
On 15 Jan 1784 Thomas Devane(1725-1817) of New Hanover Co., NC "to my beloved only son Thomas Devane, Jr.(1762-1831) for love, good will & esteem gave following..... provided Thomas, Jr.(1762-1831) has married to Margaret Devane alias Bloodworth and it's agreed that if Thomas, Jr(1762-1831)dies without issue by Margaret then Margaret is to have 1/3 of the named possessions and remaining 2/3's go to heirs of my daughter Margaret King. Signed Thomas Devane. Witnessed by Wm. Devane & Jas. Devane .wit oath Oct. 1784 by Wm Devane. Deed Book H pg 193.
Thomas Devane did marry Margaret Bloodworth .In Deed Bk H pg.206:1967, 30 Sept. 1784 Timothy Bloodworth (New Hanover Co) to my son-in-law Thomas Devane jr (same): for love....".

they had 3 children:
(1.) Peyton DeVane
(2.) Margaret Devane Bordeaux( - 11Dec 1833) m. Col Anthony Bordeaux(c.1776-1846). Named in her father's Will.
(3.) Timothy DeVane
Margaret Bloodworth Devane had an untimely death, and Thomas remarried.
According to a Revolutionary War Pension application #R2901 of Thomas Devane by his 2nd wife, Helen Stewart(1771-1845) filed7 Sept 1839, he died in January not July as the tombstone states.
Thomas married 2nd Helen Penelope "Nellie" Stewart(1771-1845) on 6 June 1792 by Rev. Mr. Lindsey a Presbyterian clergyman. In the pension application she is referred to as Helen. They lived in the Upper Black River District of New Hanover Co., NC. They had 10 known children.

1.) Stewart/Stuart Devane (1793-1861) m. Eliza Whatley
2.) Ireton C. Devane (1795-1851) m. Nancy -named in her father-in law's Will. (McPhail maybe maiden name)
3.) Patrick L. Devane (1797-1837) m. Lavice Gay
4.) Rufus Devane, Sr. (1798-1865) m. Diana Henry
5.) Mary Jane Devane (1801-1808)
6.) Thomas Devane (IV) (1803-1847) m. Eliza Ann Fennel; Eliza Ann Harvey
7.) William King Devane (1805-1846) m. Margaret Ann Fennell
8.) Franklin Devane (1807-1837) m. Mary Murphy
9.) Elizabeth Devane (1809-1809)
10.) Howard Devane/DeVane m. Eliza (she was named in her father-in-law's Will.
Thomas DeVane, IV (1803-1845) had son, Thomas,V.

Cumberland Co., NC Bibles- DeVane Family
DeVane Record copied from Bible in possession of Clarence DeVane (1896-1940), Kerr, Sampson Co., NC.
Death dates from Rev. War widow's pension application of Helen Stewart DeVane. R.2901.
Thomas DeVane wrote a Will 24 Jan 1829 New Hanover Co., NC I am working from a transcript - not the original which needs to be crossed-checked.. Names wife Helen. Children listed are:Margaret DeVane Bordeaux, Stewart & wife Eliza; Ireton C., & wife Nancy L.; Patrick L. & wife Vicey; Rufus; Thomas(IV); William K.; Franklin; Howard & wife Eliza; The Will was witnessed by James & Margaret[Canty] Devane . (James Devane was a son of John DeVane, Sr. and Margaret Canty Devane was his second wife and they had a son John Canty DeVane.).
Quoting from Vol. XXVII Num3 July 1950 The North Carolina Historical Review pg. 304( which is citing from Wheeler's Historical Sketches, II,294 Land Grant Index) "Thomas Devane, whose name is confused with that of Thomas Devane, Jr., received grants for 2,056 acres of land between 1735 and 1769. Both Thomas Devane and Thomas, Jr. served intermittently in the House of Commons from 1787 to 1792." With 3 Thomas Devanes' all in New Hanover Co., NC at that time, did the NCHR get the Thomases confused? This could have been Thomas, Jr. and son Thomas III.