British Compromise

POD (1766)
As part of a compromise agreement negotiated and supported by Prime Minister William Pitt (the Elder), the British government admits members of each colony into Parliament as voting observers, thus giving "taxation with proper representation", and diffusing the crisis (the hated "Townshend Acts" never occur). The agreement stipulates that the colonies' Governors would still be appointed by the Crown, but would also be approved by the Parliament of each Colony. With a thusly united Empire, the British is set to go on to colonize the world, much as they did in our timeline, but with the support of all of North America behind her. 1770s- the American members of Parliament begin to have greater influence in the British Parliament, and are taken more seriously than at first- though most are still considered outsiders.

Americans get their own parliament (March 1767)
As per the terms the Americans imposed to agree to the higher tax imposed by the British after the French and Indian war, on March 12th, 1767 Britain's parliament enacts the "Continental Parliament Act", which establishes a Continental Parliament and "Articles of Government" for North America. The delegates to the parliament are to be selected by the Royal Governors of each Province and they are to meet in Philadelphia the following Spring, which is considered a good middle ground for the North American colonies. Now the American parliament is created, but foreign affairs like war still ultimately go to the British parliament for approval or denial.