Stefan, your theories are brilliant, the only problem is that they are not supported by hard data.

Speaking Osten Dahl's post about "oh my god" so I investigated some other modern expressions and compared with the abbreviations. It should be said that the abbreviations may not always represent the same thing, but with these kinds of data sets, you get yet interesting results. So I have been playing around with Google n-gram viewer. Google n-gram viewer looking at books from 1900-2000 as google scanned. They claim it represents 4% of all books ever printed. More on this corpus

telephone numbers on their about page., And here in the Science article.
Note, I have zoomed in on 1940-2000 telephone numbers because it was so low frequencies before. As you may see, it is common abbreviation and it seems that it is becoming more common to write in small letters. What happened 1945-1955 and 1965-1975, I know unfortunately.
When I examined the "rofl" and "fcol" or "rolling on the floor laughing telephone numbers and" for crying out loud "I found something exciting! Born expression" for crying out loud "I wonder if the 30's?
Results for "lol" is a bit more difficult, it seems that the abbreviations have periods (1910-1920 & 1930-1940) stood for something specific. "Lol" can apparently be a name, but then it should just be a capital letter on the first and not later. "Lol cats" were very low frequency, and has many different spellings, so they could not be with
Summary abbreviation "lol", "LOL", "fcol" and "rofl" are less frequent than their full counterparts. "OMG" and "omg" is more frequent than "oh my god", the largest increase started from 1990 to 1995. "For crying out loud" perhaps originated in the 30's.
ps For Internet culture general, see the first modern lolkatten here (more on this phenomenon). Posts about the basics of lolspeak / lolcatese (also called "the new Internet pidgin") written shortly, if interested.
OMG 1947-55: Probably the beginning of the Cold War + Korean War. 1966-75: Undoubtedly the Vietnam War to the convulsions it (together with the civil rights movement and the youth rebellion) triggered in American society.
No, I was referring telephone

numbers to that it was in the time of expression of outrage, astonishment, commitment or horror OHT. That it (or one of them) just got 'OMG' was probably a coincidence of type 'a celebrity used it'. telephone numbers
Stefan, your theories are brilliant, the only problem is that they are not supported by hard data. To be honest, to get the examples that lie behind the curves. If you look just below the graph in Ngrams there are different periods telephone numbers clicking. One can also get custom-defined periods of seeking such the years 1970-1975. As you can see then that most evidence is fairly incomprehensible but in any case is not about "Oh my God." And incomprehensibility

telephone numbers can also dispelled if you go ahead and click until the actual pages from the books quoted. It turns out in this case that there is either some incomprehensible abbreviation of bureaucratic or one felskanning, or both. For example, it happened quite often that it has been "10mg." and this has become "The Omg" when scanned. I suspect that the frequency fluctuations due to chance, it's all about the right small numbers. I tried to look at the acronym "OMG" already but gave up because it was too much noise in the data. But anyone who bothered to go through the old pads and see what they are about.

Impressive, East! Of course I thought only of the time span. But, um, it was not for at least the latter of these, as also various powders made an entrance in the West outside of medical, jazz musician and artistic circles. Of course I came (luckily) not in contact with such, but can not be somethin 10mg viable in the world?
If you could only keep quiet sometimes! After zoomed in charts and picked up the calculator, I found that the 1974 rate was a