I'd argue that even though people in the united states weren't the first people to BBQ stuff, BBQ could be considered "American cuisine". And much like people elsewhere in this thread are stating with "Mexican Food" and "Chinese Food" varying wildly based on the location in Mexico/China, BBQ in the states can vary wildly based on the location it is cooked in as well.
I'd argue that even though people in the united states weren't the first people to BBQ stuff, BBQ could be considered "American cuisine". And much like people elsewhere in this thread are stating with "Mexican Food" and "Chinese Food" varying wildly based on the location in Mexico/China, BBQ in the states can vary wildly based on the location it is cooked in as well.