What is the most culturally unique of the lower 48 states?

[Sol]

Utah is culturally distinct but in a way which is very 'American' -- a lot of Mormonism is the embrace of traditional white American Anglo culture. Plus there are very similar areas to Utah in Idaho and to a lesser extent Nevada and Arizona.

Louisiana is probably the most distinctive historically, but there has been a strong degree of assimilation which makes it a good bit closer to the American 'average.'

With that in mind, it has to be NM IMO.

[Sol]

Followed by North Carolina which has not only traditional white Protestant and black populations but one of the largest Native American numbers of any state in the country. While the more urban areas like the research triangle etc have more recent immigrant groups like Indians, Arabs, Africans etc. NC also has fast growing and very diverse Hispanic populations. Along with what I read (somewhere) the largest mixed race/cultural groups in the country.

Aside from the Lumbee community, this is true of any fast-growing southern state.

In some isolated communities along the state’s coastal area it’s still certainly possible to find people who speak in an English accent in the old Elizabethan form. Or the descendants of former slaves who still somehow have retained a West African influenced form of English.

Neither of these are accurate--the "Hoi Toider" accent is distinct but not Elizabethan, while Gullah is not traditionally spoken in North Carolina except very marginally in the far Southeast---it's much more of a Lowcountry SC thing.