He definitely was in his early years. It is getting a little hard to look up as I suspect it is purposely being downplayed. Do enough research tho and it is still possible to find it.
During the 50s it was pretty common knowledge. Around 10 years ago I did the research and it was a bit hard to find but it was there. Probably even worse now.
HST was an old-timey Dem when Dems were actually pro-American. And he had the guts to drop the bomb(s) and end the war with Japan.
Stuff that was common knowledge in the 50s would leave some traces today.