Gettysburg Address ... easy question? maybe

[AussieMick]

It is my understanding that the only version written and signed by Lincoln (the Bliss copy) uses "can not"
.

I agree with you (all) that word usage evolves over time and that 'can not' may well have been more normal usage than it is now.

Its odd that many of the texts on the internet, maybe due to word processing protocols or whatever the cause, have 'cannot' for example

https://www.shmoop.com/historical-texts/...-text.html