The Two F's

[-JKP-]

Block capitals were very common in the days when letters were carved on stone, it's difficult to make curves with a chisel, but became quite uncommon during the period around the creation of the VMS, when scribes were busy writing on parchment rather than stone.

I haven't had time to look up the history of block letters to see exactly when (and why) they came back into common use but I suspect it's tied to the emergence of public school systems.