Exactly when the Elyard's went to the US is something I was planning to research soon. So far I have been concentrating on the Australian family, which I am part of, but intend to expand to other branches over coming months. The family definitely originated from the southeast of England, most notably the Kent and London areas in the 17th and 18th century. There are also Elyards in the Kent region as far back as 1550, although at present I cannot link them up. Other references have indicated the family may go back as far as the 12th/13th century, possibly even arriving with William the Conqueror, but of course these are very hard to confirm.
As you can probably tell from the lack of posts on these Elyard forums across the net, there aren't many people interested in looking up our name:(
It appears that there are a couple of distinct Elyard lines in the US, these may be linked by ancestors in England, but it is hard to trace, due to all the messy variants back then.
At present, I have been researching a related family of mine in Bermuda. Hopefully I am nearly finished with those, and I will get back to the Elyard's of England very soon. If I find out anything about when Elyards travelled to the US, I will let you know.