While the Clark/Clarke name is a very common English name, it's a fair assumption that about 75% of the current crop of New England Clarks descend from the above mentioned Thomas & John.
For the benefit of my common cousins, below is a pedigree of our Clark line going back to England, to the extent I've been able to research and confirm:
13th Great Grandfather:
Thomas Clarke (1500-1551) a nobleman from Norfolk, England, married "Catherine".
12th Great Grandfather:
Sir Thomas Clarke (1527-1580) a nobleman who settled in Hertfordshire, England, and married Martha Micklewood.
11th Great Grandfather:
William Clarke (1553-1624) from Hertfordshire, married Margaret Walker from Cambridge, England.
10th Great Grandfather:
John Clarke (1575-1623) from Cambridgeshire or Middlesex, explorer, ship worker, and ultimate settlor of Jamestown Virginia. He arrived in America on the Mary Margaret, part of the "Second Supply" fleet of ships in 1608. He was later captured by the Spanish in 1611 and held prisoner for five years until being exchanged for ransom. He likely had arrived in Jamestowne again in 1622, but was potentially killed by Indians during the 1623 massacre. His first wife, Mary Morton, died in England, and he married his second wife, Sybil Farr, just 10 years before leaving England without her.
9th Great Grandfather:
Thomas Clark (1599-1697) born in Stepney, England. He was purported to have been a shipmate on the Mayflower, but went back with the ship and its captain. This same story has been attributed to John as well, in other publications. Thomas married Susannah Ring and settled in Plymouth, Massachusetts. He was likely the eldest member of the Plymouth Colony at the time of his death at age 98. Thomas had shortened the name from Clarke to Clark upon arrival in the New World.
8th Great Grandfather:
John Clark (1637-1719), first Clark in our family to be born in Plymouth. He married Sarah Smith in Boston and became the first Clark to settle in Connecticut (Lyme). They had two sons, John and Nathaniel.
7th Great Grandfather:
Nathaniel Clark (1672-1749), born in Boston, died in Lyme, CT. Married Sarah Lay.
6th Great Grandfather:
Samuel Clark (1705-1758), born in Lyme, married Hannah Champion.
5th Great Grandfather:
Samuel Clark, Jr. (1744-1790), born in Lyme, married Ruth Graves. Samuel moved to nearby East Haddam Connecticut, and was the first Clark to settle in East Haddam, where many Clarks live today. Earlier East Haddamites were also ancestors of mine, and ancestors of many who married into the Clark line (a tangled web, for sure). Samuel was a Revolutionary War Minuteman, and served under Captain Eliphalet Holmes. He had children who stayed in East Haddam, yet some moved over into Central New York State, and have descendants still there today. I'm uncertain about what caused this migration of several hundred miles.
4th Great Grandfather:
Sterling Clark (1767-abt 1855), born in East Haddam, married Sarah Warner, and had six children, again some of whom stayed in East Haddam, others who moved to NY State to be closer to their relatives already there. Sterling himself moved to Whitestown, NY (in Oneida County), to live with his son Sterling Jr. (a doctor). Sterling Sr. was listed as blind on the 1850 census.
3rd Great Grandfather:
James Clark (1795-??), born in East Haddam, married an Anne, and fought in the War of 1812. He received a land patent in Ursa, Illinois, but sold it off soon thereafter. No trace of he or Anne past the 1821 land sale. He had five children: Infant, Delia, Harriet, James A., and Leonard Sherman, who was my ancestor.
2nd Great Grandfather:
Leonard Sherman Clark (1821-1899), born in East Haddam, was a carpenter who built many East Haddam houses which are still standing today. He married Esther Phelps Martin, and had twelve children. Many of the currently living Connecticut Clarks are descendants of Leonard Sherman. He was a Civil War veteran in Company C of 20th Connecticut Infantry Regiment; enlisted with his eldest sons John Ozias Clark and Charles Clark. They fought in the battles of Chancellorsville, Gettysburg, Tracy City, Boyd’s Trail, Resaca, Cassville, Peach Tree Creek, Siege of Atlanta, Silver Run, Bentonville, and Raleigh. Leonard was blind at the end of his life, just like his grandfather Sterling.
Niles Martin Clark (1866-1911), born in East Haddam, was the 2nd youngest child of Leonard Sherman, married Lizzie Tooker of Lyme, and had nine children: Emma, Claude, Niles, Clifford, Leonard, Ethel, Herbert, Geraldine, and James. He worked as a blacksmith, and died of heat exhaustion working in a barn in North Lyme.
Herbert Francis Clarke, born in Higganum, Connecticut, lived in Opportunity Farm for Boys, settled in Scarborough, Maine, married Emily Iva Temm and had twelve children.