You are not going to submit a portfolio for many of the schools on your list. You MIGHT submit an Arts Supplement (which would be MUCH shorter and more condensed than a portfolio) but most schools of Arts and Science are not going to ask for- or indeed read- a portfolio for a History major!
I think many of the schools which would be great fits for you are significantly less pre-professional than you think they are. Take a look at the major requirements- you are going to have a LOT of time to explore literature, art history, political science, statistics. These are not going to be places to “hone your craft” at playwriting to the exclusion of the other elements of a liberal arts education.
Don’t slice the bologna too thin!