I vaguely remember a book about a portal to different planets/stations which was located in the rural USA and there was an old civil war soldier guarding it.
1. an alien got accidentally shot.
2. some super nsa/cia/fbi ai found the immortal man.
3. paid in gold for online delivery.
4. hicks in the area stayed away from him.

CIA/FBI caught up with him and then the story continues...

[HenryAllen]

Way Station by Clifford Simak, excellent book from the 60's, thanks for reminding me of it. Also known as Here Gather the Stars in it's original publication.

thank you.