Fading memories and beautiful names. Lackawanna. Mikado. Nickel Plate. Southern Crescent. The rail lines that linked far-flung rural communities and the jewels of engineering that were created under adverse conditions are fading away - the noises and odors of railroads that once were the nation's vital lifeline and skeleton - indeed, the arm and sinew of the U.S. expansion, which stretched across mountains, plains and deserts.