There's no fiance visa. He would need either a TRV or eTA to come to Canada (or just passport if American). You would then need to get married and submit a spousal sponsorship application once married. Once you have AOR, he can then apply for a work permit. So anticipate there will be a number of months between the time he arrives in Canada and the time he can start working.
If he needs a TRV, approval may or may not happen.
