You're right Lighter. And I had been paying particular attention to that language, too. Here is how my sentences should have read:

"songs that don't *seem to* show any direct Black influence or influence from the "cotton hoosiers"

"I have focused on songs that *may have been* current during the early Irish emigrations brought on by the Potato Famine of 1845-1852."

"I am assuming that all of these songs, in one version or another, *could* have been current in New York and other eastern ports in the late 1840's and *could* have found their way to California during the Gold Rush of 1849, and thus *could* have been available in San Francisco to sail on board the "Julia Ann" on her voyages to Sydney in 1853-1855."

"Can anyone think of a reason why any of these shanties *could* not have been current then in that location?"

Not "would", but "could". And a lot of inference. At this point I will settle for "extremely likely".

Charley, it would seem that the shanty-singing was not all that remarkable at the time. Lighter is right. We just don't have documentation from anybody from that period about these songs, including my great grandfather.