From Westerly and Its Witnesses, Page 177.
The progentior of this worthy family was Martin Potter who is reported to have been a son of one of the Regicides -- One of the judges that condemned Charles I. On the restoration of the Monarchy, he fled the country, and took shelter with his cousins in South Kingston, R.I., where he lived until his death. He was reticient in respect to his history. It appears, however, that he owned a large estate in North Shields, on the banks of the Tyne, in England, in the midst of the coal region, -- property valued in 1835, at $9,000,000. Before his flight he leased this estate for ninety-nine years. At the expiration of the lease, an attempt was made to confiscate the property, and it passed into the charge of the Bishop of Durham. Measures were instituted, prior to the Revolution to recover i; these were broken up by the war. During the present century, the suit has been reopened, and is still pending. The estate embraces "something like 400 acres, one mile of docks, and near 300 houses."
There is a Vincent Potter listed as a Regicide who surrendered. And it is possible that he did visit the colonies between 1635 and 1639, before the Regicide:
From Genealogical Dictionary of N.E. (Savage) V 3 Potter, page 468
Vincent Potter of Boston came in the "Elizabeth," from London in 1635
and was next year a soldier @ the castle. May have been involved with the "Madcap
Militiamen" but evidence slight. Went home in 1639 in the same ship with....Was
afterwards questioned for regicide.
Background on Regicide
In 1649 the seventy-six judges appointed by Parliament sentenced him to death,
and fifty-nine of them signed his death warrant. After Charles I was executed,
England was ruled in part Parliament and in part by Cromwell and his son, until
1660, when Charles II, son of Charles I became King. One of the first things
Charles II did was to pardon all who had fought against his father except the
judges who had condemned him to death. He issued a proclamation announcing that
such of the judges of Charles I as did not, within fourteen days, surrender themselves
as prisoners, should receive no pardon. Ten of these judges were executed, nineteen
imprisoned for life, twenty-four had died, and a few escaped from the country.
However, Nathaniel Potter, to which this genealogy traces the Potter line in America, Immigrated in 1638 when he was 16 years old. It is not known who the parents of this Nathaniel are, and what his relationship might be to Martin and/or Vincent. Nathaniel died in 1644, 5 years before the regicide, at the age of 22.