1.  1850 Census Index/Microfilm (online at GenealogyLibrary.com):  District No. 1, Caldwell Co., KY, p. 310B, 454/454, enumerated 28 Aug 1850 (extracted by Diana Gale Matthiesen):

Wm. D. Kirkpatrick	30	M	Physician	100	Indeana
A.S.      "	30	F			Caldwell cty Ky
Aurelia Hallack	8	F			"

Aurelia HALLACK is Aurelia Skinner (COBB) KIRKPATRICK's niece, daughter of her late sister, Hannah (COBB) HALLICK. 

2.  J.H. Battle, W.H. Perrin, & G.C. Kniffin, eds.  1887. Kentucky, a History of the State.  F.A. Battey & Co., Louisville, KY (excerpts online at the Kentucky Biographies Project [link died]):

DR. W. D. KIRKPATRICK was born in Corydon, Ind., November 26, 1819, and is a son of James and Jane Dodd Kirkpatrick.  James Kirkpatrick was born in Jefferson County, Ky., in 1784, and was among the first white children in upper Kentucky.  His father, Moses Kirkpatrick, was born near Washington, in Canada Jake Valley, Penn., and coming to Kentucky when a young man, settled near the present site of Louisville.  He erected a block house on Harrod's Creek and lived there with his family for some years.  One day while out hunting at Dreman's Spring Lick, it is supposed he was captured by the Indians, for he was never seen by his family again. James Kirkpatrick was a resident in Jefferson County until his marriage in 1812.  He then lived for a short time in Henry County, Ky.  Shortly after the Indiana capital was established at Corydon, he moved to that point and there followed the trade of a tanner.  When Indianapolis was made the capital he moved to New Albany where he merchandised for a few years.  He then returned to Kentucky and settled in Canton, Trigg County.  There he sold goods until 1831 when he came to Fredonia and opened the first store that ever had been there.  He continued in business for about five years and then turned his attention to farming.  He settled near the village and there resided until his death, which occurred in 1874, at the age of ninety years.  The mother of our subject was born in Scotland, and came to this country when twelve years of age, with her parents, who settled in Henry County, Ky.  Her death occurred at New Albany in 1828. While James Kirkpatrick was a resident of Corydon, he served as associate judge for some time.  At the breaking out of the war of 1812 he raised a company, but owing to sickness in his family, he was subsequently compelled to procure a substitute.  Both he and his wife were members of the Old School Presbyterians.  Our subject is the fifth of twelve children, of whom but two are now living:  Moses, in Salt Lake City, Utah, and W.D.  The latter received his education in the old field schools of the county and worked on the home farm until seventeen years of age and then went to Paducah.  There he first clerked and subsequently ran a store-boat on the Ohio River.  He next became deputy postmaster at that point, under Frank Harrison, and remained there until 1842.  In the meantime he found time to read medicine under Drs. Lay and Brownell.  He next came to Fredonia and entered upon the practice of his profession. Since that time he has continued to have a fair practice and is now the oldest resident physician in the place.  He is a member of the Southwestern Kentucky Medical Society, the National Medical Association, and the State Sanitary Board.  He also pays attention to agriculture, owning a farm of 150 acres.  Dr. Kirkpatrick was married January 29, 1850, to Miss Aurelia S. Cobb, of Eddyville, Ky., daughter of Gideon and Modena (Clark) Cobb, natives of Vermont.  Mrs. Kirkpatrick was born in Eddyville, and is the mother of six children, of whom two are living: James D., in Kuttawa, and Moses C., at home on the farm.  Dr. Kirkpatrick is a member of Fredonia Lodge, No. 247, A.F. & A.M., and is also a member of the Old School Presbyterian Church.

3.  Messages in the Cobb Family Genealogy Forum (online at GenForum.com).