Having proof that he has applied for sponsorship and that you have been approved will probably help him when he arrives at the border.
Generally speaking, an American spouse, or partner, entering with his/her sponsor has little difficulty doing this, but it does
not guarantee if, or how long, he can remain in Canada as a visitor.
Just make sure that he doesn't bring personal items that would not be appropriate for a person just visiting Canada.
If you plan to travel by air, having a [refundable] return ticket for him would be a good idea, along with proof that he has ties back to the U.S. (home, job, bank account, etc.), just in case he encounters a CBSA officer that's not convinced that he's only coming to visit.
Good luck!