Right, so the challenge is pretty much the title. When Britain enters the colonial game, have it try and keep the (Edit: AMERICAN) colonies in some what organised. They can try and wrestle the colonies into line if required, but in essence have the various communities have a representative on a council/proto-Parliament that governs under the Crown. This means one code of law, at most one governor/appointee to represent the monarch.
Bonus Points if
1) It happens before 1700.
2) No army needs to come and stomp the colonies
3) The Parliament begins to accept local native communities as members with representatives
4) It doesn't consider itself something other than British
5) It doesn't rebel
Super Bonus Points that are completely unrelated to above
6) Slavery is never accepted as legal.