>> tried making their own script and empire. I believe it was called "Deseret":

https://en.wikipedia.org/wiki/Deseret_alphabet

It was a phonetically correct alphabet for English.

In case you are unfamiliar, in many languages, the language is written exactly as it is spoken. For example, in Spanish and Italian, words are written exactly as they are pronounced. If you can read the word, you can pronounce it though you might not know the meaning.

Children in English-speaking places will usually have to study "spelling" where they learn how to correctly spell words.

Deseret alphabet was pronounced exactly as it was written which shows which spoken accents the speakers had.