I think you will find that the movement west was encouraged by the land patents available. I have found that a member of the family would move west for the land patents and then the other members of the family would follow. My research has shown that because families settled so close to each other during the early migration from New England that they naturally inter married and this led to what I see as settlement migration, i.e., a number of families moving from NY State to an Ohio and again settling near each other. There is a site where Land Patents can be searched. I do not have the address but I am sure a simple Internet search will turn it up. Jim