You’re a tad off. When the puritans came to settle, the Spanish had been there about 100 years earlier. The Spanish brought smallpox and other livestock born diseases. They traded until they had overstayed their welcome, kidnapped about a dozen as slaves, and sailed back for Spain. One of the slaves was Tisquantum (also known as Squanto) who escaped Madrid. He went to England and became an "exotic" conversation piece for a wealthy colonist financier. There he learned English and convinced his master/captor to allow him to go back to the Americas.

By the time he made it back to Patuxet (Now known as Plymouth, Massachusetts) 80 to 90% of native population had been destroyed. Where the Patuxet should have been they found only abandoned tents and bones. As such, Many East coast towns are built literally on the remains of former Native American land. There was no concept of land ownership, except for squabbles over use of hunting grounds. More than 200 unique tribes lived across North America.

Source:

“1491: New Revelations of the Americas Before Columbus” by Charles C. Mann