I have conflicting sources:  some that say Alexander died before 1850, leaving Mary Ann a widow; others say he divorced her.

1.  Family Group Sheet by Betty Ann (Matthiesen) Cogliati, and her grandmother, Maude Irene (Thompson) Rose.

2.  Jordan R. Dodd, ed.  1993.  Missouri Marriages:  Early to 1850.  Liahona Research, Orem, UT (Broderbund CD-227):

Ervin, Alexander

Thompson, Mary Ann

Jan 31, 1844

Grundy Co.

Apparently, this must be the bond date or license date, not the date of the ceremony.

3.  1850 Census Index/Microfilm (online at GenealogyLibrary.com).  The index on the CD says "Union Town," but the location field on pages 378A to 382A is blank.  The entries for Union Town end on p. 377B; the entries for "South Fork of the American River" begin on p. 382B, and every page before and after is labeled with the location.  The record reads:  El Dorado Co., CA, p. 378A, 6/6, enumerated 24 Oct 1850 (extracted by Diana Gale Matthiesen).  In the margin, to the left it says, "Hotel."

Thomas Thompson	48	M	Hotel	4200	Ky
Mildred    "	43	F			"
Isaac D.   "	33	M	Physician		"
Mary A     "	21	F		150	Mo
[five siblings]
[seven lodgers]

Mary Ann (THOMPSON) ERVIN is a widow (or divorced) at this point, so why is she called Mary A. THOMPSON?  And where is her daughter, Delilah? 

4.  1860 Census Images (online at Ancestry.com; Image #21 of 25):  Buttsville P.O., Washington Twp., Grundy Co., MO, p. 453, PN 162, 1342/1149, enumerated 9 Jul 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):

George Spickard	37	M		Farmer	3300	1580	Ohio
Mary	28	F					Mo
Charles	11	M					"
Delila	13	F					"
John T	7	M					"
James	5	M					"
George	4	M					"
Sarah	2	F					"
Wm	9/12	M					"
Luther Bell	16	M		Farm laborer			Ind
Franklin Martin	25	M		do			Ky

Delilah IRVIN-SPICKARD is our subject's daughter.

2.  John C. Spickard.  [1987.]  "Bible Records:  Family Bible of Roy & Maude Spickard." Grundy Gleanings (Grundy County Genealogical Society, Trenton, MO) 3(3): 4.

In possession of Mrs. G.D. Pederson, Vinton, Iowa. Submitted by John C. Spickard, Spickard, Mo. George Alexander Spickard, born Sept 29, 1823 near Hillsborough, Highland Co., Ohio. Died May 30, 1899 on his farm near Spickard. Mary Ann (Thompson) Spickard, born Feb 10, 1829 Boone Co., Mo. Died Jan 28, 1911 Spickard, Mo. George and Mary Ann married Oct 23, 1851 Eldorado Co., Calif. (They came to Grundy Co. July 10, 1854) Children Delilah Ervin b. Aug 24, 1847 d. Sept 4, 1913 md. Luther Dunham Charles Smith b. Mar 14, 1849 d. Feb 12, 1880 Grundy Co., Mo Eldorado California b. Apr 29, 1853 Eldorado Co., Calif. d. July 16, 1854 John Thomas b. Oct 14, 1854 Grundy Co., Mo George Isaac Davis b. Mar 29, 1856, Grundy Co., Mo. Sarah Frances b. Feb 6, 1858 d. Dec 1893 md. ___ Denslow William Warren b. Feb 9, 1859 Grundy Co., Mo. Alexander Union b. May 6, 1862 Grundy Co., Mo. Benjamin Franklin b. May 1, 1864 Grundy Co., Mo. Mary Magdalene b. Feb 7, 1866 md. ___ Hutton Edward Augustus b. Feb 12, 1869 Grundy Co., Mo. Melissa May b. Apr 21, 1871, d. Nov 28, 1916, md. E.A. Applegate Delilah Ervin & Charles Smith Spickard were by former marriages.

Comment:  the title of this article is a mystery.  Who are Roy & Maude?  And was it really the family bible of Roy & Maude (whose family information was not included here) and not that of George & Mary Ann?  If so, the implication is that the information about George & Mary Ann is not first hand, but entered post facto by presumed descendants, which makes it a secondary source, not a primary one.

3.  John C. Spickard.  1990.  "Delilah Ervin Dunham." Grundy Gleanings (Grundy County Genealogical Society, Trenton, MO) 6(4): 1+3. Biographical sketch of Delilah, with image. 

4.  "Death Notices:  Mary A. Thompson Spickard." Grundy County Gazette, Grundy Co., MO.