The Douglas treaties were signed because Canadians wanted to settle on Vancouver Island.  The treaties were signed by the aboriginals because the aboriginals were tricked into giving up there land.  The aboriginals were  tricked into signing the treaties because they thought it was a peace treaty, since they signed with a cross they thought was the Cristian cross, it was for peace.  the aboriginals signed before the treaty was actually written and formalized. The translator they got also thought it was a peace treaty by the way it was worded.  Basically the aboriginals got scammed out of their land.