A The January 1948 issue is the one you’re referring to. The focus of the piece, however, is on the general history of the Nashville, Chattanooga & St. Louis, and the only distinct references to the changes near Cartersville are brief mentions of the line relocation and the new bridge over the Etowah River completed in 1944.
The line changes prepared the area for the construction of Lake Allatoona by the U.S. Army Corps of Engineers, which was completed in 1950. The lake was built to provide flood control, hydroelectric power, and water supply for several exurban counties northwest of Atlanta. The line relocation enabled the railroad to reduce the number of curves, and required a new bridge over the Etowah River, which feeds water to the lake.
The state of Georgia owned the Western & Atlantic, which was leased to the NC&StL. Today the line serves as a main artery for CSX Transportation into and out of Atlanta and remains under state ownership. – David C. Lester