Here is a very interesting constitutional history of the Episcopal church:

The whole thing is found here.

Here is his conclusion:

We have looked at three moments in the history of Episcopal Canon law: the initial effort to create a Constitution and Canons following the American Revolution, the attempt in the years before and after World War I to create a more comprehensive system of church law and a more modernized and centralized executive, and the effort in the 1960s to recognize the international character of the Anglican Communion.

It is always dangerous to speak about a movement or trajectory to history, so please take what I am going to say with appropriate skepticism.  I think that what we have seen is a movement away from an early minimalist view of authority to a more comprehensive form of government that is both more centralized in the U.S. and more involved in the Anglican Communion.

One of the interesting things about the current moment in the Episcopal Church is that the two movements that have long gone side by side—more centralized authority in the U.S. and deeper relationship with other Anglican church—seem now to be set at odds against one another.