Note that it looks like that website was not written by an indigenous person and instead by an outsider.
Here is where the writer indicates that the land was bought:
From what I have read so far... it didn't look as though they were selling.
Here is a copy of the alleged treaty:
Of course I will have to read up on it because I don't know the history of Long Island. It's about time I do. What I find odd (and annoying) is how invisible they seem to be. I really think they should make themselves more visible and more vocal because it is their place.
Where are they?
Who are they?
Why haven't I heard about them?
Why haven't I heard them?