Timber products I would guess but like you I can't find any information on it at all. Just found some information on my bookshelf. Mostly a variety of agriculture products are grown there plus it is a source of hickory, maple, and oak
Looks like a region tht follows the west side Appalachian river valleys that contains a whole lot of coal and oil. The first oil booms were in W.V. and NE Pennsylvania, and the Bradford Fields reached well into that part of New York state, as well as Ohio and eastern Kentucky. Birmingham, at the end of the region, is near coal fields and I think iron mines as well; U.S. Steel had a major plant in that area. iirc it's all part of the same geological structure.
Googling the different industries in each state will probably give the whole picture. For instance:
Red Mountain is a long ridge running southwest-northeast and dividing Jones Valley from Shades Valley south of Birmingham, Alabama. It is part of the Ridge-and-Valley region of the Appalachian mountains. The Red Mountain Formation of hard Silurian rock strata lies exposed in several long crests, and was named "Red Mountain" because of the rust-stained rock faces and prominent seams of red hematiteiron ore. The mountain was the site of the Sloss, Republic Steel, Woodward Iron and Tennessee Coal and iron mines which supplied ore to Birmingham's iron furnaces.
Ores like manganese was extensively mined in the ridges that line the Shenandoah Valley at one time. It seemed to peter-out at the end of WW-1 with a brief resurgence in WW-2.