Thanks for the insights.  It is amazing to me that the presence of a border agent at cross over points would lead to people killing each other, but what do I know.

Growing up in N Ohio, we routinely traveled to the border area of the US and Canada.  Obviously these are very distinct countries, but the relationship was more like "visiting your aunt and uncle's home".  It is polite to knock, but everyone knows that you are always welcome.

Believe it or not, all that was needed was for the driver of the car to show their drivers license and everyone in the car was allowed through - both directions. 

Commercial traffic was even more organized, as auto companies had component factories on both sides of the border, so that traffic was expedited.

I guess this is what is called a soft border?

Unfortunately, crossing this same US / CAN border today is immensely more complex.  Sometimes it seems even harder than flying into Germany.