Communication: from snail mail to email
(Based on Speaking Freely: A Guided Tour of American English (Flexner/Soukhanov), pp. 47-55)
It's hard to imagine communicating with others without the Internet or cell phones -- or even regular landline phones or the telegraph. But such was life in the early 1800s. We'll outline here some of the major inventions and changes affecting communication in the United States during the past 200 years.
Mail was of course the main way to keep in touch until the mid-1800s, and the only really inexpensive way to keep in touch until the last 30-40 years. Usage stays pretty constant in COHA during this time, as does post office. (By the way, it's interesting that Americans get their mail from the post office, while the British get the post from the Royal Mail).
The frequency of telegraph probably mirrors really nicely what happened in the "real world". It increases steadily through the 1800s and then reaches its peak during about the 1870s to the 1940s, after which it goes into a consistent decline. Similar frequencies are found for Western Union and maybe the best is for telegram.
(Tele)phone also matches really nicely what has happened in the "real world". It appears for the first time in the 1870s and then increases pretty every decade since that time. As far as changes in collocates, one hundred years ago we had apparatus and magnet (indicating the early stage of the invention) and tinkle (the sound it made). In the last 40-50 years, however, we have cell, computer, dial (since the operator doesn't connect you manually), and cord (since they aren't on a wall anymore).
Some words and phrases related to (tele)phones: the rise and fall of switchboard and phone booth, the rise in yellow pages since the 1950s, Touch-Tone and cordless phones since the 1970s, and telemarketing since the 1980s.
Finally, it's interesting to note two shifts in terminology. The chart at the left shows an almost unbroken increase in phone at the expense of telephone from the 1880s on. The chart at the right shows the increase in give someone a call in the place of give someone a ring since the 1920s.
Finally, there is e(-)mail, which has of course increased tons in usage in the "real world" during the last twenty years. The only thing I'll mention here is the shift in COCA from the cumbersome electronic mail to the shorter e-mail and finally the maximally short email. This is consistent with a general principle of language change, which is the shift towards "economy".