By the 1630s, the English had become a power in the region. They saw the Pequots to the west, in Connecticut, as a rival power. In 1637, a force led by the Massachusetts Bay and Plymouth colonies destroyed the Pequots. They burned an undefended Pequot village at Mystic River, killing 700 men, women, and children. Other Indians, even those that sided with the English, were appalled at the Europeans' savagery.
Some details that After the Mayflower didn't include:
The Pequot Massacre: An Exercise in Seeking Truth From Facts
"The surviving Pequots were hunted but could make little haste because of their children, Mason wrote, 'They were literally-run to ground...tramped into the mud and buried in the swamp.' The last of them were shipped to the West Indies as slaves...John Winthrop...governor once more,...[offered]...forty pounds sterling for the scalp of an Indian man, twenty for the scalps of women and children. The name 'Pequot' was officially erased from the map. The Pequot River became the Thames and their town became New London."
For more on the subject, see Losing Ground in After the Mayflower and Quality of After the Mayflower.