As the English and Dutch settlers began to expand into the Connecticut River Valley, the stage was begining to set for conflict between the settlers and the native Pequot people. The aformentioned Mohegans had, at one time, been part of the same tribe as the Pequot, but split from them under the leadership of Uncas. Despite an agreement they had signed not to meddle in trading on the Connecticut River, in 1634, a band of either Pequot or Niantic Indians murderded a group of Narragansetts headed for the Dutch trading post, The House of Hope. Because of this, the Dutch held Tatobem, a Pequot, for ransom and cut off trade with the Pequot. The Pequots then started peace negotiations with the colonists. But the Dutch demanded insane tributes and that the Pequot turn over the killers, whom the Pequots didn't have in the first place.
Later that year, things were made worse when John Stone was murderded by the Pequots. It is often said that John had forced the Pequots to act in self defense, however, most simply chose to ignore this fact and place full blame on the indians. Then, two years later, John Oldham, a friend of the Narragansetts, was murderded in his boat. The killers were not Pequot, but the Pequots gave them shelter anyway. In revenge to an attack led by John Endicott, the Pequots attacked Wethersfield on April 23, 1637, killing 30 and kidnapping two girls.
This event in American history is rarely heard of, and even more rarely truly known and fully understood. However, this war is a very good example in showing the overall struggle between the Native American peoples and the europeans that lasted for a long time after the initial colonizing of the eastern coast. Also, as Alden T. Vaughan mentioned in his book New England Frontier: Puritans and Indians 1620-1675:
"The effect of the Pequot War was profound. Overnight the balance of power had shifted from the populous but unorganized natives to the English colonies. Henceforth [until King Philip's War] there was no combination of Indian tribes that could seriously threaten the English. The destruction of the Pequots cleared away the only major obstacle to Puritan expansion. And the thoroughness of that destruction made a deep impression on the other tribes."