https://en.wikipedia.org/wiki/Wiscon
http://wiscon.net/about/history/
http://sf3.org/history/a-history-of-wiscon/
It gets about a thousand attendees each year, which makes it similar to, or slightly larger than, Eastercon, the UK's national SF convention. I know a few people from the UK who go. My generaly impression is that it's very highly regarded.
https://en.wikipedia.org/wiki/Wiscon
http://wiscon.net/about/history/
http://sf3.org/history/a-history-of-wiscon/
It gets about a thousand attendees each year, which makes it similar to, or slightly larger than, Eastercon, the UK's national SF convention. I know a few people from the UK who go. My generaly impression is that it's very highly regarded.