need a new H1B for Canadian to reentry US?

Does Canadian Citizen holding H1B visa need to re-apply a new H1B visa when re-entry US?

I am Canadian citizen. I asked a US border officer about re-apply H1B visa when I went back to Canada. He told me no need to re-apply a new H1B visa. And I passed the US border in Vancouver without any problem. I just showed the border officer my H1B notice. They even did not stamp my son's passport. ( He is H4)