The history of punctuation is bound up with the most important shift in the theory of writing to have taken place in our culture. The written word began as a record of speech, a priority of voice over text which held sway in the ancient world and was literally (i.e. graphically) enforced. Reading meant reading aloud; texts were the libretti of performances so there was no need for elaborate pointing. Indeed there is no need even for the most minimal punctuation of all, word division. Classical texts were copied in scriptio continua (joined-up writing with a vengeance) so that the opening of, say, 'Resolution and Independence' would have looked like this (only more so, because there would have been quirks of orthography, such as contractions and elisions, to contend with as well):

LRB 7 January 1993 | PDF Download