John Underhill was the name of my 5th great-grandfather. He was an ancestor of my great-grandmother, Delaphina (Decker) Dickinson. Previously, I had posted a blog about a book I found containing mention of Capt. John Underhill who came to America in 1630 with the Winthrop Fleet. At that time, I hadn't reached that far back in the Underhill line, but after doing some investigating, I made the connection! He was my 10th great-grandfather. Learn more about John Underhill here.
My lineage to John is as follows, starting with my grandmother:
(Source information is shown below, referenced in brackets)
Margaret Dickinson, married Lloyd Reese. Her parents were:
Delaphina Decker, married William H. Dickinson. Her parents were:
Lydia Mayo, married Charles Decker. Her parents were:
Oscar Mayo, married Lycenia Strong . His parents were:
Raymond Mayo, married Saloma Underhill [1, 2]. Her parents were:
John Underhill, married Sarah Barnhart [3, 4]. His parents were:
Israel Underhill, married Elizabeth Garrison . His parents were:
Bartow Underhill, married Sarah . His parents were:
Nathaniel Underhill II, married Mary Hunt [6, 7]. His parents were:
Nathaniel Underhill, married Mary Ferris [8, 9]. His parents were:
Capt. John Underhill, married Elizabeth Feake 
 Oscar Mayo death certificate #90413, Wyoming County, Pennsylvania. His parents names given as Raymond Mayo and Salome Underhill. His brother, Albert's death certificate, however calls them Raymond Mayo and Hannah Underhill.
 Raymond H. Mayo [Findagrave]
 Underhill Genealogy Vol. 6, p. 1539, John Underhill, born bet. 1780-1785 in New York, married Sarah Barnhart. They were in Broome County, New York in 1830 and 1835 when the census were taken and moved to Susquehanna County, Pennsylvania, in 1839. There they both died in 1851. Saloma Underhill, who married "before 1850 Raymond Mayo", is listed as one of their children.
 History of Northeastern Pennsylvania, by J.H. Beers, p. 272. "Mrs. Kiefer's paternal great-grandfather, Israel Underhill, a farmer by occupation, was born in England*, and was married in New York State to a woman of German birth. He died in Orange County, N.Y., in 1822, aged 76 years. The paternal grandparents, John J. and Sarah (Barnhart) Underhill, were born, reared and married in New York, and in 1839 removed from that State to Dimock township, Susquehanna Co., Penn., where the grandfather engaged in farming. Both died in 1851, at the age of seventy-six years, and were buried in Susquehanna. The children were Dewitt C., father of Mrs. Kiefer; Sarah M., deceased wife of Joshua Stage; Barto, who died in California; and Saloma, deceased wife of Raymond Mayo." *Notice, Beers reports Israel being born in England, but states that his parents were born, reared, and married in New York.
 Underhill Genealogy, Vol. 5, p. 115-116, states that Israel Underhill was born before 1755 in Westchester County, New York, and died in Newburgh, Orange County, New York. He married Elizabeth "Betsy" Garrison, daughter of Richard and Jane (Gerow) Garrison. According to this source, Israel was overlooked by Mrs. Frost and other family genealogists, partly due to his name being recorded in family records as "Isaac", and partly because his sons left Ulster and Orange Counties and crossed the Hudson river after the Revolution, settling in Plattekill, a substantial distance away, breaking family ties.
 Early wills of Westchester County, New York: from 1664 to 1784 : a careful abstract of all wills (nearly 800) recorded in New York Surrogate's Office and at White Plains, N.Y. from 1664 to 1784 : also the genealogy of "the Havilands" of Westchester County and descendants of Hon. James Graham (Watkinson and Ackerley families) : with genealogical and historical notes. New York: F.P. Harper, 1898, p. 365. [Link]
 Underhill Genealogy, Vol. II, p. 87-88. [Link]
 Colonial Families of the United States of America, Vol. VII, p. 464-465.
Underhill Genealogy Vol. 1-4, Josephine Frost, published by Myron C. Taylor, 1932. [Link]
John Underhill, captain of New England and New Netherland, by Henry C. Shelley, 1932. [Link]
The Frost Genealogy, by Josephine C. Frost, p. 375-376 [Link]
Journal of Gov. Winthrop [Link]
Winthrop Fleet [Wikipedia]
John Winthrop [Wikipedia]
John Underhill (captain) [Wikipedia]