Thomas Elwood marries:

1) Nancy "Mamie" or "Nannie" Goodrich, 1835-1882 on 5 June 1862.

Their children; Mary Louisa, John Goodrich, Nellie Goodrich, Miriam, and Love

Indiana records shows:
Indiana, Marriage Collection, 1800-1941
Name: Thomas E. Clark
Spouse Name: Nannie M. Goodrich
Marriage Date: Jun 1862
Marriage County: Randolph
Performed By: S. T. Stout
Source Citation: Title: Randolph County Indiana, Marriage Record 1858-1865, Compiled by Margaret Snyder;; Page: 5.
Source Information: Ancestry.com. Indiana, Marriage Collection, 1800-1941 [database on-line]. Provo, UT, USA: Ancestry.com Operations Inc, 2005.

2) Martha Jane
Their children;
Judy and Mamie

1880 U.S.Federal Census Record
Name: Thomas E. Clark
Event Type: Census
Event Date: 1880
Event Place: Perry, Wayne, Indiana, United States
Gender: Male
Age: 45
Marital Status: Married
Occupation: Merchant
Race (Original):
Ethnicity: American
Relationship to Head of Household: Self
Birthplace: North Carolina, United States
Birth Date: 1835
Spouse's Name: Naney M. Clark
Spouse's Birthplace: Indiana, United States
Father's Name:
Father's Birthplace: N. Carolina, U.S.
Mother's Name:
Mother's Birthplace: N. Carolina, U.S.
Page: 62
Page Letter: B
Entry Number: 1956
Affiliate Film Number: T9-0321
GS Film number: 1254321
Digital Folder Number: 004240666
Image Number: 00675
Household Gender Age Birthplace
Self Thomas E. Clark M 45 North Carolina, U.S.
Wife Naney M. Clark F 42 Indiana, U.S.
Daughter Mary L. Clark F 16 Indiana, U.S.
Son John G. Clark M 12 Indiana, U.S.
Daughter Nellie Clark F 11 Indiana, U.S.
Daughter Mariam Clark F 6 Indiana, U.S.

Source Citation: Year: 1880; Census Place: Perry, Wayne, Indiana; Roll: 321; Family History Film: 1254321; Page: 62B; Enumeration District: 056; Image: 0673.
Source Information: Ancestry.com and The Church of Jesus Christ of Latter-day Saints. 1880 United States Federal Census [database on-line]. Provo, UT, USA: Ancestry.com Operations Inc, 2010. 1880 U.S. Census Index provided by The Church of Jesus Christ of Latter-day Saints © Copyright 1999 Intellectual Reserve, Inc. All rights reserved. All use is subject to the limited use license and other terms and conditions applicable to this site.

I requested a photo of the headstone. The general problem they reported is:

I searched the stated plot or section and could not find the grave. Contributor reporting error: http://www.findagrave.com/cgi-bin/fg.cgi?page=mr&MRid=47228659

If you know where he is buried, please let me know so I can update this page.

son Dr John Goodrich Clark