Way back in 2011, I wrote about the expression “full stop” (BrE for AmE “period”), specifically to emphasize what the speaker has just said.
According to a Christian Science Monitor blog post, the trend has continued and, seemingly, intensified:
Before announcing his presidential bid, former Maryland Gov. Martin O’Malley made clear in December his disdain for the CIA’s highly controversial interrogation tactics. “I don’t believe the United States should torture,” he said. “Period. Full stop.’’
More recently, George Washington University political scientist John Sides was asked in May if early polls were relevant to who would take office: “They are not. Full stop.” A month later, Republican Rick Santorum, queried on Bruce Jenner’s decision to become Caitlyn Jenner, responded: “My job as a human being is to treat everybody with dignity or respect – period, stop, full stop, no qualification to that.” That same month, Iowa pollster J. Ann Selzer discussed Hillary Clinton’s supposed political invincibility in the Hawkeye State: “The reality is, this is a field where nobody has effectively stepped up to challenge Hillary Clinton, full stop.”
Just four days ago, in a speech in Kenya, Barack Obama said: “If somebody is a law-abiding citizen who is going about their business and working in a job and obeying the traffic signs and doing all the other things that all citizens are supposed to do, and not harming anybody, the idea that they are gonna be treated differently or abused because of who they love is wrong, full stop.”
notoneoffbritishisms.com 
Obama was speaking in Kenya where British English is the official language
I found this interesting and can’t really comment regarding the use of this expression in the U.S. I remember my mother used to enjoy a satirical history book called “1066 and all that.” The last line in the book goes something like “America then became the top nation and history came to a.”
The period presumably is intended to be to understood as “full stop”
In the UK I quite often hear people nowadays using the expression “end of” (which I take to be short for “end of story”) when they intend to bring a discussion to an end. Once I imagine they may have used “full stop.”
CHAPTER 62
A Bad Thing
AMERICA was thus clearly top nation, and History came to a .
Ha Ha Picky! It’s Clearly needing updated but when everyone had to learn English history I found this book extremely enjoyable. Thank you for correcting the quote!
I imagine many of the Americans using this phrase understand it solely as a rhetorical device, and wouldn’t use the term to refer solely to the punctuation mark itself.
Why not?
Yes, in the same way that Brits would never use the word “period” to mean a punctuation mark, but might well use it rhetorically.
I have heard “period” used rhetorically in England, but never come across it used as a term of punctuation. If you were dictating a passage over the phone here and said period (for punctuation) most people would not know what it meant.
In Western movies, persons dictating telegrams use ”stop”. Always struck me as curious and unnecessary,
You had to ask for punctuation, and pay for it. If the message would not be clear without the period, you asked for the STOP, and paid for it as a word.
A bit like people using radio phones saying ‘Over’ and ‘Roger’
Period in UK English is a term used extremely widely for that part of a woman’s menstrual cycle when she is bleeding. Period meaning full stop is never used as a consequence…