Another thing to look into for crossing if you have children. A few years ago everyone needed a passport, kids included. Then they changed it so only the parents needed a passport and kids could travel with birth certificates.
Now here is where it gets sticky. Enhanced licences. It used to be adults, WITHOUT children could cross with an enhanced, but if you had kids with you the adults needed full passports unless the kids had passports.
Currently, parents with only an enhanced licence CAN cross with children who only carry a birth certificate. However during times of high security and Amber Alerts they may not allow it.
So long story short, it is best for all adults in your group to have a full passport instead of enhanced licences unless you want to risk having to leave some of your kids at the border.