The most Episcopalian state is...Rhode Island?

[King of Kensington]

Here's the states where they're at least 3% of the population.

Rhode Island  4%
Connecticut  3%
Maine  3%
Maryland  3%
New Hampshire  3%
Virginia  3%

[King of Kensington]

The Pew religious landscape study:

https://www.pewresearch.org/religion/religious-landscape-study/

[King of Kensington]

And yes they are:

Congregationalist

Connecticut  5%
Maine  4%
New Hampshire  4%
Massachusetts  3%
Vermont  3%

Less than 1% everywhere else (including Rhode Island).

[King of Kensington]

DC is the most Episcopalian of the metros...ahead of Boston/NYC/Philly.  I guess that makes sense that DC is more Protestant, has virtually no WWC and Episcopalianism attracts both northeastern and southern elites.