the jefferson highway was an automobile highway stretching through the central united states from new orleans, louisiana, to winnipeg, manitoba, canada. the jefferson highway was replaced with the new numbered us highway system in the late 1920s. portions of the highway are still named jefferson highway, for example: the portions that run through jefferson parish, louisiana; east baton rouge parish, louisiana; lee's summit, missouri; osseo, minnesota; and wadena, minnesota.