Postcard Birmingham is a work always in
progress by Warren Reed
Pre - 1907, yes, smoke was once considered a sign of a healthy economy.  Tennessee, Coal & Iron Rail Mill at Ensley.  TCI was bought  by U.S. Steel.  Even today, some refer to Birmingham's U.S. Steel's operations as TCI.

Birmingham was a major producer of railroad rail.

Card is about pre-1907, printed in Germany