After a brief slowdown of the economy at the end of the Depression , the country entered World War II , which renewed the importance of railroads . The rails were essential to transport gasoline and scrap metal to build military vehicles , so Meridian became the region 's rail center again . This renewed prosperity continued until the 1950s , when the automobile and Interstate Highway System became more popular than passenger rails . The decline of the railroad industry caused significant job losses , resulting in a population decline as workers left for other areas .