1800 William Pickett lived in Fairfield, Fairfield County, South Carolina (age 16-25 or 25-44), with 2 other males (age under 10), 1 female (age 16-25), and 1 female (age under 10) and 10 slaves. John King Senior was listed on the same page. 
1805 The will of John D King was dated September 13, 1805 and was proved in January 1807 in Montgomery County, Tennessee. It named children, including daughters Selah wife of Charles Pickett, Mary wife of William Pickett, and Rodah Pickett wife of Micajah Pickett, and 2 grandsons: John King Pickett and Thomas King Pickett.   
1805 A land survey was made for William Pickett for a 52 acre tract on the Wateree Creek branch of the Wateree River, Fairfield District, South Carolina. Survey dated and recorded May 21. Micajah Pickett, Robert Laffins, and William Pickett were adjacent landowners.  
1807 A biosketch of son Micajah reports :
William and Mary (King) Pickett, were natives of South Carolina. The family is descended from English ancestors, who emigrated to America and settled in Virginia. The father [William] came with his family to Mississippi in 1807, making the journey by a flatboat down the Tennessee and Mississippi rivers to Franklin county; there he and his wife spent the remainder of their days with the exception of a few years passed in Sicily Island, La.
1810 Wm Picket (age 26-44) lived in Orleans, Catahoula Parish, Louisiana with males: four (age under 10), one (age 10-15); and females: one (age under 10), one (age 10-15), and one (age 26-44) and 37 slaves. The adjacent listing was Mik. Pickett with oldest male (age over 45) and female (age 26-44) and 19 slaves. 
1813 William Pickett and Moses King witnessed an indenture between David Cathey and Nathan King for land in Sicily Island, Catahoula Parish, Louisiana. 
1816 A list of inhabitants of Franklin County, Mississippi includes William, Micajah Sr, Micajah Jr, and Thomas K Pickett. 
1823 William Pickett and Micajah Pickett Jr, of the state of Franklin County, Mississippi, appointed James Pickett of Greenfield District, South Carolina as their attorney to recover any assets due to them in the states of North and South Carolina. 
1828 Micajah Pickett Jr of Franklin County, Mississippi, residuary claimant on bond of Micajah Pickett to his wife Kissanah Pickett, wants to close the matter, so he agrees to payment of $1,500 to James Pickett for care of Kissanah. Rufus K Pickett and William Pickett, heirs to the estate of William Pickett Sr deceased, late of Franklin County, Mississippi agreed to the same. Dated September 8. 
1841 William Pickett, William Bull, and Lewis Stevens posted bond for William Pickett as guardian of R.K. Stevens and Lewis Stevens, in the Yazoo County Orphans Court. Dated January 25. Lewis Stevens was appointed guardian of Mary Ann Stevens. 
1846 The will of Mary Pickett was presented to the probate court in Yazoo, Mississippi on January 26. :
This day William Pickett and M Pickett Jr personally appeared before the Hon Probate Court of Yazoo County and on oath testified that during the last sickness of Mary Pickett deceased she did make known to them at her residence as witnesses her last will and testament as follows, viz To Cassandra Stevens, Martha, Ann Stevens, Micajah P Stevens, James M Stevens, Laura Stevens and Benjamin F Stevens and William Stevens, children of her daughter Celia Stevens, she gave to following negroes Hairah, Mussan Philip, Daphney and Winny as To Rufus R. Stevens and Levis Stevens children of her daughter, Mary Stevens an Negro boy Josha sworn to & subscribed in open court this 26th Jany 1846 Chas M Henderson. William Pickett, M Pickett Jr.
William Pickett further states that she bequeathed to Elizabeth Stevens, and Mary Ann Stevens her Baroncke? and Horse in his presence and the presence of his wife Elizas Pickett
Sworn to & subscribed in open court Jany 26 1846 Chas M Henderson ccp Recorded Feby 2st 1848. William Pickett.
1848 William Pickett and Micajah Pickett [sons?] put their plantations in Jackson County, Mississippi up for sale.
About 1807 William Pickett & Mary left Fairfield County, South Carolina. In 1809 they were in Catahoula Parish, Louisiana and in 1815 they moved to Franklin County. (Later Yazoo County was formed from Franklin). After William's death in 1827, Mary moved to Yazoo County with some of her children, where she lived for the rest of her life. 
There is a Picket Island in Catahoula Parish, Louisiana.
We list the names of several children based on the research of others. We seek further documentation about the children of this couple.
Seaborn Pickett  has also been named as a child by some researchers. However, Seaborn was listed in the 1850 census as born in North Carolina before the marriage of William Pickett and Mary King. Perhaps Seaborn was not a child of this couple.
 United States Federal Census, 1800, [FamilySearchImage], [FamilySearchRecord].
 Tennessee, Wills and Probate Records, 1779-2008, Montgomery County, Wills, Inventories, 1797-1818, A-174, [AncestryRecord], [AncestryImage].
 Alta Kennard Patterson, Virginia Fern Mitchell, ed., Kennard King Knight Hardin Goodin Their Ancestors & Descendants (Chelsea, Michigan: BookCrafters, 1988), 97-98, [GoogleBooks].
 Reba Shropshire Wilson, Betty Shropshire Glover, The Lees and Kings of Virginia and North Carolina, 1636-1976 (1975), 125, [GoogleBooks].
 Commissioner of Locations, South Carolina, Camden District, Plat books, 1785-1841, A2-51, [FamilySearchImage], [FSCatalog].
 South Carolina Department of Archives and History, Series: S213192, Fairfield, Plat Books (Columbia), Vol. 40-418, [Image], [Search1], [Search2], [Search3].
 Biographical and Historical Memoirs of Mississippi, Vol. 2, (Chicago: 1891), 597, [GoogleBooks].
 United States Federal Census, 1810, [FamilySearchImage], [FamilySearchRecord].
 Carol Young Knight, First Settlers of Catahoula Parish, Louisiana: 1808-1839 (1983), B-54B, [GoogleBooks], [USGenWeb].
 Dunbar Rowland, The Official and Statistical Register of the State of Mississippi, Volume 4 (1917), 97, [GoogleBooks].
 Greenville County, South Carolina Deed, Q-157, [FamilySearchImage], [FHLCatalog].
 Greenville County, South Carolina Deed, Q-158, two deeds, [FamilySearchImage], [FHLCatalog].
 Mississippi, Wills and Probate Records, 1780-1982, [AncestryRecord], [AncestryImage].
 Mississippi, Wills and Probate Records, 1780-1982, Yazoo, Will A-106, [AncestryRecord], [AncestryImage].
 The Weekly Mississippian, Jackson, Mississippi, Dec 08, 1848, page 4, [NewspapersClip].
 rootsweb source no longer available.
 Janet and Robert Wolfe, Genealogy Page for Seaborn Pickett, [JRWolfeGenealogy].