Like many L&N trains, the "Pan-American" experienced a surge in ridership during World War II, carrying four times its normal traffic. The "Pan-American" lost its title as the L&N's flagship train in 1946 with the introduction of faster "Humming Bird" over the same route. Although never fully streamlined, the "Pan-American" began receiving streamlined equipment in 1949. The southbound "Pan-American" carried through sleepers for Nashville, Tennessee, Louisville, Kentucky and Memphis from New York City conveyed by the Pennsylvania Railroad in Cincinnati. Further south in Montgomery, Alabama it received New York-New Orleans and Washington-New Orleans sleepers from the Southern Railway's "Piedmont Limited".