What a great debate. I would have assumed it's Gaelic in origin based on the sound and the fact that a lot of Famine-era Irish immigrants were in California at the time, but the comments from Irish speakers indicate it's not likely.
There was a lot of flexibility and inventiveness in the English language and modes of communication at the time (mid 1800s). Besides the flood of immigrants and the rise of literacy and mass media, this was the era of the telegraph and the Pony Express. The US Postal Service measured mail in the half ounce at the time (https://about.usps.com/who/profile/history/domestic-letter-r...), which led to a creative method of saving postage and writing paper called "cross writing" (https://easygenie.org/blogs/news/mysterious-letter-from-the-...)
There was a lot of flexibility and inventiveness in the English language and modes of communication at the time (mid 1800s). Besides the flood of immigrants and the rise of literacy and mass media, this was the era of the telegraph and the Pony Express. The US Postal Service measured mail in the half ounce at the time (https://about.usps.com/who/profile/history/domestic-letter-r...), which led to a creative method of saving postage and writing paper called "cross writing" (https://easygenie.org/blogs/news/mysterious-letter-from-the-...)