Sources:

1. Census records, any of those indicated.

2. Records of descendants/researchers of this family

3. History of Washington County Pennsylvania, Earle R Forrest
pub. 1926, Chicago, The S J Clarke Publishing Company
accessed at Ancestry.com
Vol 3 pg 131,132, biography of William L Kline, husband of Louisa Sedgwick:
"Mr Kline was married at Rices Landing, June 25, 1884, to Miss Louisa Segwick, who was born at that place October 6, 1854, the daughter of Samuel and Prudence (Arnold) Segwick. Her father was born at Meadow Run, Greene county, Pennsylvania, in 1813 and died in 1866. He was a well-known citizen of his community, where he had successfully followed the mercantile business for a number of years. Politically he was a Democrat, while socially he was a member of the Masonic order, in which he had attained the Knight Templar degree in the York Rite and the thirty-second degree in the Scottish Rite. He was the son of Thomas Segwick, who was born in Greene County, of English extraction."

4. History of Greene County Pennsylvania
pub 1888, Samuel P. Bates, Chicago
accessed at Ancestry.com
pages 635-636, biography of Elias Stone, son of James Stone and Nancy Sedgwick:
"Elias Stone, deceased, who was a farmer and stock-grower, was born in Greensboro, Greene County, Penn., September 22, 1808. He was a son of James and Nancy (Sedgewick) Stone, who were natives of Greene County, and descended from its earliest settlers. The history of the families on both sides shows them to have been farmers, usually, and of Irish descent. Mr. Stone was the second in a family of eight children. He was reared in Monongahela Township, this county, where he attended the subscription schools. He devoted his business life to farming and the growing of fine stock. In 1833 he married Mary, daughter of Samuel and Nancy (Lackey) Huston. Her parents were natives of Pennsylvania and of Irish descent. Mr. and Mrs. Stone were the parents of three children, Lizzie, Nan and Fannie. The mother died in 1843. Mr. Stone was a Republican in politics, and a member of the Methodist Episcopal Church. He was twice married, and his widow and two children, Frank and Amanda, survive him. He died in 1872."

5. Marriages, Deaths & Misc. Items from the Waynesburg Messenger
Transcribed at by James Fordyce (genealogy@fordyce.org)
accessed online at http://www.fordyce.org/genealogy/GCRecords/
a. August 22, 1866: Deaths. "At Rice's Landing, on the 3d inst., of general debility, Mr. SAMUEL SEDGWICK, aged 58 years. He had been a citizen of that place for thirty-seven years, and was a most estimable man."
    Note that Forrest's History of Washington County Pennsylvania lists his birth as 1813,
    but this obituary is selected as a more timely source.
b. October 12, 1864: MARRIED, Oct 6th, by Rev. J. S. Gibson, Mr. THOMAS C. HUFTY, of Bacyrus, Ind., and Miss LIZZIE SEDGWICK, of Rice's Landing, Pa.
    Both Samuel and Joseph had daughters Elizabeth of an age to be this woman;
    all Ancestry trees show her daughter of Joseph but age of daughter of Samuel.
c. March 23, 1864: DIED, At Farmington, Utah Territory, Jan. 22d, 1864, THOMAS SEDGWICK, aged 29 years, formerly of Rices' Landing in this county.
    This would be the eldest son of Joseph Sedgwick

6. Greene County, Pennsylvania Will Indexes
Transcribed at the Greene County Recorders Office by James Fordyce (genealogy@fordyce.org)
accessed online at http://www.fordyce.org/genealogy/GCRecords/Wills1.txt
Will or
Estate
File No.Registry DateSurnameGiven NameExecutor or
Administrator
BkPgDate of Death
Estate464Jun 24 1824SedgwickMathewBarbara Sedgwick1254 
Estate2296Sep 25SedgwickSamuelWm. A. Sedgwick4163 
Will3261Apr 4 1882SedgwickJosephT. H. Sedgwick5343Mar 3 1882

7. Stone Family Bible
accessed at Ancestry.com

8. Cemetery records of Greene County, Pennsylvania
compiled Dorothy T. Hennen, pub Waynesburg, Pennsylvania: D. T. Hennen, c1975-1980, 1993
accessed at FamilySearch.org June 22, 2012
These records:

   Vol 3 pg 152 Glades Cemetery Charmichaels, Greene, Pennsylvania
   Stone  Elizabeth  d. 11-12-1885 aged in her 79th yr
          Rebecca    d. 4-13-1894 aged in her 75th yr
          Mary A wife of elias 1831-1909
          James      b. 7-22-1818
          Nancy      b. 5-28-1818  d. 1-18-1884
          Nancy      d. 8-24-1888 in her 52nd yr
          Jennie W.  b. 8-18-1870  d. 8-27-1953
          Thomas     d. 11-12-1879 aged 69yr 1mo 14da
          Mary Ann   d. 11-15-1854  aged 32yr 2mo 4da
            wife of Thomas Stone
          Elias      d. 11-22-1872 aged 64yr 2mo
          Mary, his wife  d. 5-4-1843 aged 39 yr
          Esther     d. 4-30-1869 aged 44yr 3mo 12da
            wife of Thomas Stone
          Margaret   d. 9-14-1864 aged 10yr 5mo 7da
            dau of Elias and Mary A Stone
          Nancy      d. 9-4-1856 aged 70yr 10mo 7da
            wife of James Stone
          Nancy      d. 3-11-1855 aged 8mo 20 da
          Infant Son 7-29-1850
            two children of T & M.A Stone
          Jacob L    1835 - 1917
          Margaret R 1831 - 1912
          Nancy      d. 10-12-1850 aged 26yr 4mo
            dau of J & N Stone
          Thomas     d. 10-3-1845 aged 2yr 6mo 18da
            son of Elias & Mary Stone
          James      d. 5-14-18_6 aged ? - 1da -?
             son of E & M Stone
          Viola      d. 9-16-1861 aged 5mo 18da
          Milton     d. ?-5-1864 aged 6yr 2mo 3da
          John A     d. 6-11-1864 aged 1yr 6mo 5da
          Robason G  d. 9-19-1864 aged 6yr 6mo 5da
            four children of Elias & Mary J. Stone

     Vol 9 pg 578,581,588 Hewitt Cemetery, Rices Landing, Greene, Pennsylvania
     Sedgwick  Samuel     d. 8-2-1866, aged 57yr 9mo 7da
               Joseph     d. 8-23-1855, aged 2yr 9mo 7da
                 son of S & F Sedgwick
     Sedgwick  Joseph     b. 10-5-1811 d. 3-3-1882
     Sedgwick  Margaret   1883 - 1920
               Samuel     1879 - 1910
               Susan W    1845 - 1884
               William A  1843 - 1887

9. Records of Hewitt Cemetery, Rices Landing, Greene, Pennsylvania     Map
Transcribed by Robert Efaw, accessed at http://www.pa-roots.com these records:
LAST NAME FIRST NAMESECTION
SEDGEWICKabt 1853 - 1855JOSEPH (s of S. & F. ) 
SEDGEWICK1811 - 1882JOSEPH1-26
SEDGEWICK LUCY DOWLIN1-26
SEDGEWICK 1883 - 1920MARGARET1-22
SEDGEWICK Mrs. JOSEPH1-26
SEDGEWICK1809 - 1866SAMUEL 
SEDGEWICK1879 - 1910SAMUEL1-22
SEDGEWICK1845 1884SUSAN1-22
SEDGEWICK THEODORE, DR.1-26
SEDGEWICK1843 - 1887WILLIAM A.1-22

9. Greene County, PA - Death Records
transcribed Jul 2001 by James Fordyce
accessed 3/25/2010 online at http://www.usgwarchives.net/pa/greene/deaths.htm
This record:

   Page Ln  Surname  Given Name  Color  Sex     Age  M or S  Place of Birth
   148  31  Sedgwick Prudence    white  female  70   married Greene Co.
     Date of Death  Place of Death      Cause of Death  Duration Illness
     June 1 1894    Jefferson township  Dropsy          7 mo.
       Place of Interment  Date of Interment  Date of Record
       Hewitts G. Yd.      June 2, 1894       June 18, 1894

Questions? Have more data? genealogy@sedgwick.org