NameJohn Wilcox 
Birthca 1762, Maryland
MemoHe was born on the east shore of Chesapeake Bay.
Death1823, Sangamon County, Illinois
Spouses
Birth04 Feb 1774, Goochland County, Virginia259
Death1842, Sangamon County, Illinois
Marriage23 or 24 Feb 1796, Mercer County, Kentucky260,261,262
Martha (Died as Child) (~1792-~1806)
Research notes for John Wilcox
Just got on an Ancestry Web site that has transcribed a copy of "History oif the Early Setlers of Sangamon County, Illinois: "centennial Record". It was printed in 1876. There is a lengthy section on John and Lucinda Wilcox and their children. It mentions that John died about 1823 and Lucinda died about 1842. Someone else in the family had to supply the information.
It mentions that John and Lucinda married in Oldham Co., Kentucky, but gave no date. It goes on to say that they had 11 children:
two were born in Oldham Co. (Mahala? and Stephen?), they then moved to Davidson Co., Tennessee where one child was born (Ellis?), and then moved to Logan County Kentucky where 8 children were born (?: Martha, Edith, Elizabeth, Nancy, Eliza, William, Joshua, and Frances). At the time the book was printed, Stephen, Ellis, William, Joshua, and Frances (female) are all still living. One of them would have had to provide the information..probably not Frances as it says she resides in Jacksonville, Illinois with her brother-in-law, Stice (probably Andrew Stice, who was widowed from Nancy Wilcox, Frances' sister).
One other note: In this family detailed discussion, no mention is made that John and Ellis are twins. Since each was alive during the time it was made, IF they had been twins it would have been mentioned.
I am now inclined to believe Stephen and Ellis are not twins and Stephen was probably born in Kentucky. If Stephen's wife was providing the Census information, maybe she was just mistaken. I will try to go back to the later Census images of Stephen and Harriet's children and see if any of them list their father being born in Kentucky or Tennessee. Since he died after the 1850 Census, and that's the only one I have that says he was born in Tennessee, maybe the mistake only appears in THAT census.
The family information also says, they moved in 1818 to St. Clair Co. Maybe it will be able to backtrack from that date to figure out when they married, having 11 children. I have to go for now to pick up a daughter
bye, Melanie
Biography notes for John Wilcox
EARLY SETTLERS OF SANGAMON COUNTY - 1876
By John Carroll Power
These biographies were submitted by a researcher and evidently abstracted from the 1876 History of Sangamon County, IL. Errors could occur, so one should always verify the correctness by obtaining copies of vitals and performing all necessary research to document what is contained herein.
WILCOX, JOHN, was born in Maryland on the eastern shore of the Chesapeake Bay. His parents died when he was quite young, and to keep from being bound out, he ran away, embarked on a sailing vessel and went to the West India islands, returning to Maryland, and when he was sixteen or seventeen years old went with a family to Virginia, and from there to the vicinity of Danville, Kentucky. He was married in Oldham county, Kentucky, to Lucinda Oglesby. She was born in Loudon county, Virginia, and her parents moved to that part of Shelby which afterwards became Oldham county, Kentucky. Her father, William Oglesby, was a soldier in the Revolution. John Wilcox and his wife had two children in Oldham county, and moved to Davidson county, Tennessee, where one child was born, and then moved to Logan county, Kentucky, where eight children were born. In 1818, the family moved to St. Clair county, Illinois, and from there to what became Sangamon county, arriving in the fall of 1819, about six miles east of where Springfield now stands, and settled between the mouths of Sugar creek and the south fork of Sangamon river. Of their eleven children--
MAHALA, born in Kentucky and married Thomas Moore. They had three children, and she died August 18, 1855, and Thomas Moore died April 28, 1866, both near Berlin, Illinois.
STEPHEN, born in Kentucky, married in 1824 to Harriet Newell. They had eight children. He died March 22, 1858, and his widow lives with her youngest son, STEPHEN, near Blue Mound, Macon county, Illinois.
ELLIS, born in Davidson county, Tennessee, about 1790, married Feb. 24, 1824, in Simpson county, Kentucky, to Ann Lewis, who was born Dec. 21, 1800, in Pendleton district, South Carolina. They had two children in Kentucky, and moved to Sangamon county, Illinois, arriving in 1828, in Island Grove, where they had five living children, namely, LUCINDA, born February 15, 1825, in Simpson county, Kentucky, married in Sangamon county to Thomas Rhea. See his name. NERIAH L., born in Kentucky, died in Sangamon county, aged ten years. THOMAS, born June 28, 1831, in Sangamon county, married Catharine Ruble. They have eight children, CHARLES L., ALBERT N., BENJAMIN F., MARY A., WALLACE B., FRANCIS, CLARENCE and RUTH S., and live in Morgan county, six miles west of Berlin, Sangamon county, Illinois. JOHN F., born Feb. 12, 1836, in Sangamon county, married July 24, 1863, to Mary A. Rhea, had one child which died in infancy, and Mrs. Wilcox died May 16, 1865. He was married August 7, 1866, to Fanny Scott. They have three children, JAY GALE, N. ELLIS and NELLIE, and live three-quarters of a mile northwest of Loami, Illinois. CHARLES H., born May 10, 1838, married Sept. 11, 1864, to Caroline Caruthers, have two children, and lives with his father. SAMUEL M. died Jan. 29, 1863, in the twenty-third year of his age. JOSIAH L., born Nov. 26, 1844, in Sangamon county, married May, 1861, to Alice V. Parker. They had one child, JOE A., and Mrs. Wilcox died Jan. 29, 1862. Dr. Joe L. Wilcox was appointed, May 19, 1862, second assistant surgeon of the 11th Ill. Cav., was promoted May 19, 1863, to first assistant surgeon, served to the end of the rebellion, when he was mustered out with his regiment, October, 1865. He was married Nov. 9, 1865, to Jean F. Patteson. They have three children, DWIGHT, AUGUSTUS P. and ANNIE. Dr. Wilcox was elected, November, 1874, as one of the representatives of Sangamon county in the twenty-ninth general assembly of Illinois, and is a practicing physician at Loami, Sangamon county, Illinois. Ellis Wilcox and wife now--1876--reside where they settled in 1829. It is five miles west of Berlin, Sangamon county, Illinois.
MARTHA died in her fourteenth year.
EDITH, born in Kentucky, married in Sangamon county to Duke Chilton, and died, leaving her husband and two children at Oneco, Stephenson county, Illinois.
ELIZABETH died, aged twenty-two years.
NANCY married Andrew Stice, and died August, 1871, leaving her husband and four children at Jacksonville, Illinois.
ELIZA married William Oglesby and died in 1843, leaving two sons, JOSEPH and STEPHEN, near Belleville, Illinois.
WILLIAM, born August 9, 1813, in Logan county, Kentucky, raised in Sangamon county, was a soldier in the Blackhawk war, married Nov. 8, 1835, in Oldham county, Kentucky, to Nancy Ellis, had five children, and Mrs. Wilcox died Oct. 2, 1852, leaving two children, ELLIS O. and GEORGE W. He was married Nov. 9, 1856, to Mary Wilbourne. They have two children, CHARLOTTE and WILLIAM BEN. E., and reside three miles west of Berlin, Sangamon county, Illinois.
JOSHUA, born in Kentucky, raised in Sangamon county, married twice, and lives west of Berlin, Illinois.
FRANCES is unmarried and lives with her brother-in-law, Stice, at Jacksonville, Illinois.
John Wilcox died about 1823, and his widow died in 1842, both in Sangamon county, Illinois.
Research notes for John & Lucinda “Lucy” (Family)
DATES: Marriage date conflicts with the birth dates of a number of the children. Need to verify it is 1796 and not 1790?