1. Sampson POWER , Sr. died between 1720 and 1730 in Lower Norfolk, Virginia.
The book "Cavaliers and Pioneers" lists the arrival of Sampson Power. He is one of 60 persons transported by Thomas Fenwick. Fenwick is rewarded with 3000 acres of land in Norfolk County, on the Elizabeth River, on 28 Sep 1681. That would place Sampson's arrival around 1681.
Sampson Power (frequently shown as Powers) is a witness on several wills in lower Norfolk between 1697 and 1720.
Starting in 1730, we see only Mrs. Elizabeth Power (and her slaves) on the list of tithables in Lower Norfolk. We assume his death comes sometime between the last will he witnessed (1720) and his wife's appearance on the tithables (1730).
We are fairly sure that Sampson is the son of Sampson Sr. We are also persuaded that Samuel is also a son, although there is -- to date -- no proof. There are several other possible children including a James Power (who marries 4 Aug 1762 an Amy Spratt, widdow of James Spratt).
As noted above, Thomas Fenwick is the man who gets the "headright" of land for Power's transportation. Fenwick is a gentleman, son of Walter Fenwick of Atwick in York (England). Thomas Fenwick gets two pieces of land in the Norfolk area and a large parcel of land in Maryland, where he eventually settles and becomes a government official (Thomas Fenwick, by Edwin J. Sellers, Philadelphia, 1916).
There are two notable factors involving Fenwick. First, the land he is given is similar in location to the land we see Sampson's son Samuel selling later. And second, all the names on the passenger list with Sampson Sr. are very English. That fact, plus the wills and other legal paperwork he witnessed and the existance of books in his son's library at his death persuade the author that Sampson Power was English and quite possibly from Atwick.

He was married to Elizabeth UNKNOWN. Elizabeth UNKNOWN died about 1736.
Starting in 1730, we see only Mrs. Elizabeth Power (and her slaves) on the list of tithables in Lower Norfolk. And in 1733, the list includes a son Sampson Junior. We assume that is the year he turned 16. Sampson and his mother's last appearance on the list of tithables is 1736. Sampson POWER , Sr. and Elizabeth UNKNOWN had the following children:

child+2 i. Samuel POWER.
child+3 ii. Sampson POWER.