Phantom - there is not just one article that I'm aware of. There are many articles, however, they are often practice-type specific. So, you'll have to read a number of them to get a good idea.
For example, the ASHP Journal has had many articles over the years which illustrate how institutional (whether its acute or rehabilitative) pharmacy practice has changed. The most recent review, I think, was in 1999 - really quite a bit old!
There have been many articles about changes in community practice. There are also articles on more specific areas, oncology, nuclear, pediatric pharmacy practice - each in their own journals. There have also been changes in academic pharmacy practice to keep up with teaching new pharmacists.
So...where to start??? Are you in a university with a library? They can help you do a Pub Med search. Your key words will be "pharmacy practice change" "history of pharmacy practice" "community pharmacy" "hospital pharmacy" "medication therapy management" ....perhaps more, but that will get you started. Otherwise, you can do a google search, but you often can't access the articles unless you subscribe to the journal which is why a library is a good place to go.
Good luck! Come back if you need more help!