— born in Indiana:
4.  Catherine JOHNSONBAUGH, b. 1835, Jackson Twp., Wayne Co., IN 
5.  Henry JOHNSONBAUGH, b. 1836/7, Jackson Twp., Wayne Co., IN
6.  Minta JOHNSONBAUGH, b. ca. 1838/9; d.s.p. bef. 1850
7.  Margaret Ann JOHNSONBAUGH, b. 1841/2 
8.  Hannah A. JOHNSONBAUGH, b. 1844/5 

1a.  Anon.  1966.  Marriage Index:  Ohio, 1789-1850.  Liahona Research, Orem, UT (Broderbund CD-400):

Johnsonbaugh, John

Wise, Hannah

Jan 29, 1828

Wayne Co.

1b.  Marriage Index:  Indiana, 1851-1900 (Broderbund CD-243):

Tam, Silas J.	Johnsonbaugh, Elizabeth	Feb 15, 1859	White Co.
Johnsonbaugh, Daniel	Ferguson, Frances	Apr 11, 1864	White Co.

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

1830

Johnstonbaugh, John

OH

Wayne Co.

Jackson Twp.

p. 133

3.  1840 Census Index and Digital Images (online at Ancestry.com; Image #31-32 of 40; extracted by Diana Gale Matthiesen):

1840

IN

Wayne Co.

Jackson Twp.

p. 318

John Johnsonbaugh

111 001 - 210 001

0100000

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	4 or under	1835-1840	= Henry (b. 1836/7)
1 male	5-9	1830-1835	= Daniel (b. 1830/1)
1 male	10-14	1825-1830	= George (b. 1829)
1 male	30-39	1800-1810	= John (b. 1800)
2 females	4 or under	1835-1840	= Minta = Catherine (b. 1835)
1 female	5-9	1830-1835	= Elizabeth (b. 1832/3)
1 female	30-39	1800-1810	= Hannah
1	person engaged in agriculture

Listed three lines above brother Henry JOHNSONBAUGH, who is listed one line above brother David JOHNSONBAUGH. 

4.  Census Microfilm Records:  Indiana, 1850 (Broderbund CD-302) and 1850 Census Index/Images (online at Ancestry.com; Image #20 of 28):  Liberty Twp., Delaware Co., IN, p. 315B, 323/323, enumerated 17 Sep 1850 (extracted by Diana Gale Matthiesen):

John Johnsonbaugh	50	M	Farmer	1000	Penna
Catharine   "	31	F			"
George      "	21	M	Farmer		Ohio
Daniel      "	19	M	"		"
Elizabeth J "	17	F			"
Catharine   "	15	F			Ind
Henry       "	13	M			"
Margaret    "	8	F			"
Hannah      "	6	F			"

The image on the Broderbund was very difficult to read, but the image at Ancestry.com couldn't be clearer.  I have no doubt the ages here for John and Catharine are correct, which ages are at odds with the WFT.

5.  Census Records, Indiana, 1860 (Broderbund CD-304):

6.  Family Quest Archives:  Indiana 1870 Census Index.  Heritage Quest ACD-0038:  not found.

7.  Esther Weygandt Powell.  1971/73.  Early Ohio Tax Records.  Ohio Genealogy Society, Akron, OH (repub. 1983 by Genealogical Publ. Co., Baltimore, MD; repub. 1999 as Broderbund CD-651).  On p. 14 (n.b., that Ashland Co. was not formed until 1846; in 1810, Jackson Twp. was in Wayne Co.):

EARLY ASHLAND COUNTY AREA - HOUSEHOLDERS... LIST OF VOTERS IN JACKSON TOWNSHIP  October 1827... Johnsonbaugh, John...

8.  Anon.  1894.  A Portrait and Biographical Record of Delaware and Randolph Counties, Ind.  A.W. Bowen & Co., Chicago (biographies online at countyhistory.com):

GEORGE JONSONBOUGH... The ancestors of Mr. [George] Jonsonbough were natives of Pennsylvania, in which state his father, John Jonsonbough, and mother, whose maiden name was Hannah Wise, were both born.  They were married in Wayne county, Ohio, January 29, 1828, and later moved to Indiana, locating in White county, where Mr. Jonsonbough followed his trade of coopering until his death in September, 1878.  His wife died a number of years previous, having been called to her final rest on the 21st of November 1846.  John and Hannah Jonsonbough reared a family of eight children, whose names are as follows:  George, whose name introduces this sketch; Daniel; Elizabeth, deceased; Catherine, deceased; Henry; Minta, deceased; Margaret, wife of James Richie; and Hannah, wife of Perry Godlove...

9.  Broderbund.  World Family Trees.  Vol. 28, Pedigree #297.  Has both John and Catherine born in 1799, but see above census record.  Apparently, they read both their ages as 51 (and I can see how one might have), but I'm quite certain they are 50 and 31, respectively.