About copyright and public domain

Public domain of US writen books

[Gusgsm]

Good morning

Talking about copyright

The writen works in its original form of an US writer that died in 1937 (that is: 70 years ago) are already public domain or not yet?

Excuse me, but in legal matters I am a bit challenged

Thanks :)

[ccDan]

What year was the book published in the U.S.? If it was published before 1923 (I think), it is, with some exceptions, in the public domain.

After 1923, it may or may not be in the public domain, depending upon whether the copyright was renewed.

If it was never published, I don't remember what the rules are on that. I've never dealt with an unpublished old work.

[Gusgsm]

Thank you :)