I found this blog post about Edward Oaksmith's mother, Elizabeth Oakes Smith that has some information on Edward:
http://lorenelizabethchristie.blogspot.c...fe-in.html
and her papers at the University of Virginia:
https://ead.lib.virginia.edu/vivaxtf/vie...u03614.xml
Apparently, even though Elizabeth was a Unionist and opponent of slavery there was an effort to paint her as a southern sympathizer at the time of her death. The "anecdote" of son Edward possibly being a member of the conspiracy probably arises from that. I can find no mention of it before the 1890's. Elizabeth did have a son, Appleton Oaksmith who did support the Confederacy as a blockade runner, was caught and then escaped from a Boston prison in 1862 and fled to London.
Here's a link to a brief 1880 bio of Edward Oaksmith:
https://books.google.com/books?id=g2lsPj...22&f=false
He translated the play
Narcisse from the German in 1863. He also apparently was an artist:
http://figure-drawings.blogspot.com/2009...-feet.html
and
http://nyeandcompany.com/auctions/70/a-c...ry-98.html
