Reason or "Rezin" Bowie Sr. was born in September 1756,  in Orange County, North Carolina, the son of James Bowie and Sarah Whitehead. There has been no lack of speculation regarding the origin of the name "Rezin" or "Reason". The brother of Sarah Whitehead was Reason Whitehead. The name came from the Whitehead family.
Disputed date of birth
Many have accepted a 1762 birth date for Reason Bowie, in order that he will fit the narrative of his father James being the son of John Bowie & Elizabeth Pottinger of Prince George County, Maryland. John Bowie's will in 1839 named heirs, including a son James, who disappeared from the record, and many subscribe to the theory that he later became the James Bowie who was the father of the Southern Bowies.
According to three older D.A.R. records listing family sources, he was born in Sept of 1756.
DAR # 469065, Mrs. Gloria Bryant Alley, Rezin Bowie, born Sep 1756
DAR # 468359, Doris McKinzie Boyd, Rezin Bowie, born 1762. (The year was crossed out in DAR Headquarters, Wash DC, and corrected to read, Rezin Bowie, born Sep 1756),
DAR # 627156, Mary Alice Horner Scott, Rezin Bowie, born Sep 1756
DAR #150599, Mrs. Wilma Louise Moore, Rezin Bowie, born Sep 1756
Deposition of Henry Karr relative to the Bowie Family
Confirming list of children of James Bowie and Sarah Whitehead
Written in Spanish
New Feliciana, 4th District, April 18, 1800
Before me, John O'Connor, Alcade of the said [p.606] district, appeared Henry Karr, and having taken an oath on the Holy Gospel, he declared that he has known James [Diego] and Sarah Bowie, in the State of Georgia, United States of America, for about twenty years, more or less, and that he knew nine children that they had anmed: [named:] Reason, John, Reece, Ana, Sara, Mary, Elay, Martha and Comfort. 
Revolutionary War Service
1 Jul 1781 - Richmond County, Georgia
Col Dunn's Regt, 2 Division
Quartermaster's Report: Reson Bowie, Spie, Fodarin to Spies & Wagon, Horses, 10 & 1 horse, 7 mos servis (sic). /s/ James Bowie, J P, 16 Jun 1782 
Rezin married Elvira "Elve" Jones on 8 Mar 1782 in Savannah, Georgia. 
Migration to Tennessee in 1787
My father and mother were both born in the state of Georgia. They were married in 1782 in the county of Burke of the same state; my mother's maiden name being Elvira Jones; my father's name was Rezin Bowie. During my infancy , or about the year 1787, my parents moved from Georgia to the state of Tennessee, where they remained for six or seven years.
In Sumner County, Tennessee, 1790, Reason Bowie was listed in "A List of the Taxable property in Captain Joseph M Elluraths Company for the year 1790" with 400 (acres) land and 1 White Poll and 3 Black Polls. 
Records in Logan County, Kentucky 1794
Records in Logan County, Kentucky Deed book dated 5 Jul 1794
John Jones, Deceased's heirs Phereby Jones - Stephen Jones - James McDaniel - Reason Bowie - Hiram O'Neal - Ann Lamar - Selah Jones - Marab Jones to Zach Askey one negro girl. consideration 76 L 13 sh - p.32
5 Nov 1794 - Abraham Buford, Scott Co., ky. - to Morton Maulding, Logan Co., Ky. - consideration 400 L current money of Kentucky. - 395 a. land = Logan County to Wipperwill Creek. Wit: Robert Ewing - Justinian Cartwright - Reason Bowie - Thomas Gorham. p.40
5 Nov 1794 - Abraham Buford, Scott Co., Ky. To Morton Mauldin - consideration 400 L current money. 395 a land in Logan County on Whipperwill & spring creek. WIt: Justinian Cartwright - Robert Ewing - Thomas Goram - Reason Bowie. p. 88
Livingston County, Kentucky 1800
On Feb. 19, 1800, he moved to Livingston County, Missouri, on the Ohio River.
Bowie family members, Reason, "Rhue" and "Alesy" are listed in the Kentucky Tax records for 1800 along with brother-in-law Jesse Bouding (Bowden).
FIsh Lake Missouri 1801
Thomas Hugg, jun. and Ch's Huff, under Rezin Bowie, claimed 380 arpents in June 1801 on Fish Lake.
Rapides District, Louisiana 1802
Rezin Bowie moved to Louisiana around 1802 and is considered to be the founder of the Louisiana branch of the family.
...and in 1802 he came and settled on the Bushley Bayou, in what was then the district of Rapides, Louisiana, and under Spanish rule. Here he reamined till 1809, when he again, and for the last time, took up the line of march, and finally settled in the district of Opelousas, where he remained until he died, in 1819, in the fall of the year.
William Roe...states that he is well acquainted with the land, which is situated near the Big prairie, about three miles from the Cattahoula courthouse, adjoining lands originally owned by Resin Bowie, now the property of Abraham Bird; that it was actually settled and in cultivation on and before the 20th day of December, 1803, being first settled in the summer of 1803, by Resin Bowie, and afterward by Thomas Hubbs for years, and always known and called the property of said Hubbs
Opelousas District, Louisiana 1809
In 1809, the family moved again (and for good), south to St. Landry Parish, Louisiana. This is where his son Jim Bowie finally grew up.
Land Claim in Attakapas - 1812
Rezin Bowie claims 640 superficial acres of land, situated on the right bank of Bayou Vermilion, in the county of Attakapas.
Rezin Bowie died in 1821 in Opelousas.
He sleeps with the common mother Earth, without any stone or inscription to mark the resting-place of him whose bosom was so often bared, and whose hand was so often raised for the defence of his family, and the homes and firesides of his countrymen, against the secret and deadly attacks of savage foes. At his death he left four sons, myself being the eldest, Rezin, James and Stephen, and two daughters.
Lavinia Bowie (1783-1783);born in 1783 in Richmond County, Georgia. and died in 1783 in Burke County, Georgia.
David Bowie (1884-1803); born in 1784 in Washington County, Georgia. and died in 1803 at age 19.
John Jones Bowie (1785-1859); born in 1785 in Washington County, Georgia. and died on June 22, 1859 in Bowie Plantation, Chicot County, AR. at age 74
Sarah Bowie (1786-1815); born in 1786 in Washington County, Georgia. and died in 1815 in Opelousas, Saint Landry Parish, Louisiana at age 29
Martha Bowie (1791-1845) ; born in 1791 in Burke County, Georgia. and died in 1845 in Shreveport, Caddo Parish, Louisiana at age 54. James Nugent, 2nd Alexander B. Sterret, 1st settler of Shreveport, LA
Mary Bowie (1792-1842); born on May 4, 1792 in Sumner, TN. and died on August 10, 1842, in Hollywood Plantation, East Baton Rouge, Louisiana at age 50.m. Abraham Bird of Missouri.
Rezin Pleasants Bowie Jr., (1793-1841); born on September 8, 1793 in Elliott Springs, (near Gallatin) Sumner County, Tennessee. Rezin Jr., married Margaret NEVIL, on September 15, 1814 in the Saint Landry Parish Roman Catholic Church
↑ Source: #JENNINGS p. 16 "Records of West Florida, East Baton Rouge Parish, LA Courthouse, Vol. IV, pp. 213 -
200. During 1936 - 1939 the Spanish records were translated into English by the W.P.A. under the supervision of Mr Stanley Clisby Arthur, State Superintendent of Federal Archives in Louisiana, and five copies of the badly deteriorated original volumes of the Spanish records were made. These five copies were bound into 19 volumes. The original books and one set of the transcribed volumes are in the Courthouse of East Baton Rouge Parish,
LA. West Feliciana Parish at St. Francisville, La, Tulane University in New Orleans, LA, University of Southeastern Louisiana at Hammond, LA, and the State Library of Louisiana also have copies. The Church of Later Day Saints Library in Utah has a microfilm of the records.
↑ Georgia citizens and soldiers of the American revolution. Davis, Robert Scott. Neblock, Hillary. Easley, South Carolina : Southern Historical Press, c1979
Source: S-1035467511 Repository: #R-2144939563 U.S., Find A Grave Index, 1600s-Current Ancestry.com Publication: Ancestry.com Operations, Inc.
Repository: R-2144939563 Ancestry.com Note:
Source: S-2111779185 Repository: #R-2144939563 Ancestry Family Trees Publication: Online publication - Provo, UT, USA: Ancestry.com. Original data: Family Tree files submitted by Ancestry members. Note: This information comes from 1 or more individual Ancestry Family Tree files. This source citation points you to a current version of those files. Note: The owners of these tree files may have removed or changed information since this source citation was created. Ancestry Family Tree http://trees.ancestry.com/pt/AMTCitationRedir.aspx?tid=5981775&pid=588
It may be possible to confirm family relationships with Rezin by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
However, there are no known yDNA or mtDNA test-takers in his direct paternal or maternal line.
It is likely that these autosomal DNA test-takers will share DNA with Rezin: