On the Copy of An Old Marriage Record in the Maine State Archives, Samuel is listed as a resident of Portland, Maine and his wife, Lydia Stover, is listed as a resident of Freeport, Maine. They were married on May 6, 1826.
He died August 17, 1877, and was buried at the Pittsfield Village Cemetery in Pittsfield, Somerset County, Maine, at age 75. 
The 1850 census for Unity, Waldo, Maine, a Joiner lists Samuel H. Whitten as 44 years-old, born in Maine with wife Lydia 53-years-old, born in Maine, and Samuel, 20 years-old, born in Maine, who is a Shoemaker.
In the 1860 census includes Samuel H. Whitten as 57-years-oldSamuel H. is living in Waldo, ME, with:
Was the Justice of the Peace Samuel H. Whitten the carpenter (the father) or Samuel M.R. Whitten the watchmaker (the son)? We know these two Samuels are different because they both appear in the same 1856 directory.
There is a random reference to a marriage performed "by Samuel F. Whitten on 3 Dec 1837" here.
There is a Samuel H. Whitten who was recommended for an appointment as a trial justice in Troy, Maine (1860) and then Somerset County (1870).
"Secretary of State Correspondence Record: Petition to recommend the appointment of Samuel H. Whitten to the office of Trial Justice for Somerset County. Associated names: ... Albion Whitten; Samuel H. Whitten".
And again for Samuel H. Whitten, "Petition to recommend the appointment of Samuel H. Whitten to the office of Trial Justice for Somerset County, 20 Mar. 1870.
Could the middle initial H. stand for Hover? His grandson was named Albion Hover Whitten.
Other old notes
This 1953 compilation WHIDDEN OF GREENLAND, NH, AND WHITTEN OF KENNEBUNKPORT would seem promising but there doesn't appear to be a connection with this line. The closest it comes is a Samuel Whitten of Saco, born June 23, 1803, who married Lucinda Ladd. He was the father of a Samuel Emery Whitten, born November 10, 1834, died November 26, 1856. There is no Lydia Hoover, Lydia Mitchell, or Edward Whitten in the document.
There is a third Samuel Whitten in Waldo in the 1860 census, in addition to Samuel the father and Samuel the son. This Samuel is age 63 (born about 1797), living with:
Mary Whitten, age: 64
Hannah Whitten, age: 36
Oliver Whitten, age: 25
Weston Whitten, age: 10
Mary Getchell, age: 9
Fredrick Whitten, age: 7
Find-a-Grave memorial 79476769 is for Samuel Whitten, born Jun. 23, 1803, in Saco, York County, died Jan. 17, 1868, in Saco. Husband of Lucinda Ladd, father of Emery, Leonard, James, Melinda, and Frances. Are we sure none of our info on Samuel H. Whitten is being confused with him? Whitten-1 16:03, 24 July 2013 (EDT)
↑ The 1850 census has him as 44, implying a birth year of 1806. The 1860 census has him as 57, implying a birth year of 1803.
↑ Found by Michael Lechner: "6 May 1826 Samuel H. Whitten of Portland and Lydia Stover of Freeport" from Maine Genealogist, Volumes 30-31, The Society, 2008 - Registers of births, etc, pg 143.
↑ Found by Michael Lechner: "'Secretary of State Correspondence, 1820-1914,' database, Maine Genealogy accessed 1 July 2013, entry for Petition to recommend the appointment of Samuel H. Whitten to the office of Trial Justice for Somerset County., 20 Mar. 1870, citing Hancock County Court of Sessions database, Maine State Archives. See also: Secretary of State Correspondence Search Results
↑ "Secretary of State Correspondence, 1820-1914," database, Maine Genealogy (http://www.mainegenealogy.net/individual_correspondence_record.asp?id=9031 : accessed 16 June 2016), entry for Petition to recommend the appointment of Samuel H. Whitten to the office of Trial Justice for Somerset County., 20 Mar. 1870, citing Hancock County Court of Sessions database, Maine State Archives.
↑ The middle initial H. appears in his son Samuel's death certificate, census records, etc.
Paternal relationship is confirmed through Y-chromosome DNA testing. Keith Whitten Sr. and Chris Whitten match on 37 out of 37 markers, as reported by Family Tree DNA. This confirms their direct paternal lines back to their MRCA Richard Whitten.
"United States Census, 1870," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/M66M-PKC : accessed 02 Mar 2013), Samuel H Whitten in household of Albian Whitten, Maine, United States; citing p. 28, family 226, NARA microfilm publication M593, FHL microfilm 0552058.
It may be possible to confirm family relationships with Samuel by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree:
I hadn't checked your tree earlier and having done so, don't see any names in common so your comment about "WHIDDEN OF GREENLAND, NH, AND WHITTEN OF KENNEBUNKPORT" is probably true. If I ever find any info, I'll let you know. My Whitten tree is pretty skimpty and sources hard to come by. My early years tree is largely based on that document, which I understood to be originally written by Sybil Noyes, a reputable researcher who never identified her connection but found in USA census her mother was a Whitten. Cheers, Ray