Jerry Siegel.
FINALLY! Geez! 
That was harder than it should have been. Perhaps Superman, though science fiction, isn’t what people think of when they think of science fiction.
In any case, my brain? Broken!
I have a dead guy in an envelope.
Did he live entirely in the 20th Century (i.e. born after Jan 1, 1901, died before Dec 31, 2000) ?
No, he did not live entirely in the 20th century.
Was it Teddy Roosevelt?
Assuming it wasn’t, was he born in the United States?
Ha! I almost picked Teddy Roosevelt, but no.
And no, he was not born in the US.
Was it Winston Churchill?
Assuming “no”, was he born in Asia?
No, it wasn’t Winston Churchill.
No, he wasn’t born in Asia.
Was he T. E. Lawrence?
Assuming, “no”, had he ever served in the military?
No, it wasn’t Lawrence.
No, I have no knowledge of him ever being in any military.
Was it Benjamin Disraeli?
If not, did he die in the last six years?
No, it wasn’t Disraeli.
No, he didn’t die in the last 6 years.
Was it John A. McDonald?
If not, was English this man’s first language?
No, it wasn’t McDonald.
Yes, English was his first language.
Was it George Bernard Shaw?
If not, was he born in what is now the United Kingdom?
No, it wasn’t Shaw.
Yes, he was born in what is now the UK.
Is it Isaac Newton?
If not, was he born before 1700?
Did he spend most of his life there (in the UK)?