That's a great story and incidentally a similar one to another Nebraska ISP I'm familiar with (KDSI). I think they got started when a larger industrial company had excess bandwidth. Sounds like your story was a lot of fun for a high schooler. Who did you sell it to and why?
I know of KDSI! We ended up selling to a guy starting a new business called RCOM in Kearney, NE. I worked with him for half a year getting everything transitioned. We sold our Kansas operations to telco called Nex-Tech. At the time the business was funded by my good friend's dad. Collectively we decided it was best for us to focus on our further education and go to college.