1.  Jordan R. Dodd, ed.  1993.  Tennessee Marriages:  Early to 1850.  Liahona Research, Orem, UT (Broderbund CD-229):  not found.

2.  Census Index:  U.S. Selected Counties, 1820 (Broderbund CD-314):  not found.  The 1820 Tennessee Census is extant, but on this CD, surnames beginning with letters A thru F are missing.  Please see my WARNINGS regarding use of these CDs.

3.  Census Index:  U.S. Selected Counties, 1830 (Broderbund CD-315):

1830	Hagler, John L.	TN	Henry Co.	p. 23
1832	Hagler, John L.	TN	Henry Co.

4.  Census Index:  U.S. Selected Counties, 1840 (Broderbund CD-316):

1840

Hagler, John L.

TN

Henry Co.

p. 62

5.  1850 Census Index/Microfilm (online at GenealogyLibrary.com):  6th Civil District, Henry Co., TN, p. 286A, 85/85, enumerated 26 Nov 1850 (extracted by Diana Gale Matthiesen):

John L. Hagler	62	M	Farmer	32,300	N.C.
Joyce      "	52	F			"
Mary Rains	32	F			Tenn

Living nine doors down from Widow Mary RAINS (ae 65, b. NC), and her four unmarried daughters.  The Haglers are obviously sufficiently well-off to have a "hired girl," so Mary is not necessarily related to them.  Living seven doors down from James H. CHRISMAN.