The Know-Nothings were a political party that flourished briefly in the United States during the mid-1850s. Their chief idea was to restrict Catholic immigration. Some Know-Nothings even believed the Pope wanted to take over the country.
The Know-Nothings got their name from their habit of answering “I know nothing” when questioned about their activities. Such secretiveness even carried over between Know-Nothings themselves at their meetings and ceremonies—-or even just greeting each other in everyday life.
When a (male) Know-Nothing wanted to know if a new acquaintance was a fellow member (also male), he was supposed to hold the right lapel of his coat with his right hand, and point the right index finger at his chest.
If the new companion was also a Know-Nothing, he would reply in like kind, except he would use his left lapel and his left hand. The two new friends would then shake hands in the customary way.
But the rituals didn’t stop there. Know-Nothing number one would now draw his index finger across the palm of his hand—right or left finger and palm not specified. Number two then did the same, after which the pair would link the ends of their index fingers together.
Now it was time for some spoken signs. While still linked together, the first Know-Nothing would whisper, “Is that yours?”, to which the second would whisper back, “It is.” The first one would whisper in reply, “How did you get it?”, to which the second one would whisper, “It is my birth right.”
Then, at long last, the two members would converse normally, though by now a considerable number of passersby must have gathered to watch, which would hardly have been conducive to the secrecy which the Know-Nothings sought.
Should a Know-Nothing be speaking carelessly with an unauthorized person, a passing second Know-Nothing could display a “note of caution,” by sliding his index finger and thumb in front of his eyes, while keeping his other fingers clenched, the message being “keep dark.”
There was a distress call too, i.e., “Oh, oh, oh,” to which the correct answer was, “Hio, hio, h-i-o.”
The Know-Nothings’ secretiveness even extended to secret writing, using a substitution plan not unlike the old Captain Midnight Decoder rings:
A was a 1, then B was 7, and so on, with C-13, D-19, E-25, F-2, G-8, H-14, I-20, J-26, K-3, L-9, M-15, N-21, O-4, P-10, Q-16, R-22, S-5, T-11, U-17, V-23, W-6, X-12, Y-18, and Z as 24.
A professional code breaker presumably would not have much trouble with this, quite apart from the fact that this code and also the hand signals were all written up on page 2 of the July 14, 1855 Daily Baltimore Republican anyway.