Like others said, in an old home there won't be a gap - but there will likely be some damage right at the bottom - there is a piece of trim made SPECIFICALLY for this!
It's called quarter-round, its just as it's called, a fourth of a circle, made to fit in the right angle of baseboard and floor. Inexpensive and easy to install
We've ripped up carpeting in three old homes so far, with nothing but good things to say about having it gone!
