I believe my grandfather, Alan Schaffer (he may then have been using the first name "Alfred" or "Flip") was a columnist for the National Guardian during its first year of publication in 1948. But I can't find any archives for that newspaper that go back far enough; most of them seem to start in the 60s. Are there any suggestions as to where I might look? I have a university affiliation so I should be able to get access to most such things.
The archives exist on microfilm. I doubt they've been fully digitized. You can search Worldcat.org to find the copy nearest to you. If you have access to inter-library loan, it's possible that you could have a copy shipped to you free of charge, but a lot of libraries are hesitant to lend out their microfilm materials. I was able to access the National Guardian archives from the early 1950s at the Emory University Library (as a non Emory student).
Of course, in-person archival research is complicated by the current pandemic, so you'll have to find out what the individual library's policies are and decide whether it's safe to make the trip.