Is Passport Required For 4 Months Child?

[yaahhuu]

I'm travelling to the USA by road this week (5 days stay) with my sister and nephew (4 months old). We all have Canadian passport except my nephew, would they allow him to cross the border? The only ID we have for my nephew is his Canadian birth certificate.

Thanks...

 

[Triple Citizen]

They most likely will grant him entry. However, for future ease, ensure the kid has his own passport.