The family surname “Rial” is really just the Olde English spelling of the modern word “Royal”.It seems that Ryal, Rial and Royal were used synonymously in colonial America.
The reason for the confusion is that English usage has changed.Today, those of us who were educated in modern times, assume that our language has always been structured similar to what we know.That is simply not the case.
In the English language, the spelling Royal came into existence when a board of scholars was asked to recommend standardized spelling for English words.Before that time English words were spelled phonetically.
If you read Olde English Literature, you will find considerable variation in spelling from modern English.
The history of the name “Rial” before 1820 could have been spelled any number of ways and still have been correct.
Arthur Royall conducted a single surname study, recording statistical data on the occurrence of the name and its variations.
Historically, English did not have the letter “I”.Remember the vowels AEIOU and sometimes Y.The sometimes Y, comes from the substitution of the letter Y for the I sound.Therefore early spellings included Ryal, as the 1913 Webster’s Unabridged Dictionary indicates with the note [Spelt also ryal.].