That hole is probably part of the "curing" system. They used wood fire to cure the tobacco.

I saw some tobacco curing structures in Kentucky which are different from North Carolina, but had the same objective.

I like the photo and the young man in the door.

Tobacco is not a sin, nice story anyway

My grandfather grew up share-cropping on tobacco farms in Person County, NC during the Great Depression. He was finally able to purchase a farm of his own with help from the GI Bill after serving in Europe during WW2. Though we are all aware of the sins of tobacco, the relatively high dollar value of tobacco allowed small farm holders to eek out a living for their families. I spent several summers of my youth working in his fields in Caswell County, as well as for other farmers in Person, Orange and Vance counties. I'm glad for the experience, but would never choose to do it again.

My father is the same age as the boy in the photo.
Wish Lange had backed up and put more of the barn
in the photo. That one is a fairly nice model!
The hole is for smoke more than likely, as many
of these barns were heated with chopped wood. The
farmer would split wood all winter and spring to
have enough wood to cure the tobacco in the summer.
While this child may look poor, farm children fared
better than city folk during the Great Depression.
I helped harvest tobacco from age 8 to 18. It's
hot sticky work.

Might want to put a little weatherstripping on that foot-wide hole in the wall

Very serious worker.
I dig his toes.