I am madly trying to research two turn of the twentieth century lines that have been made famous in blues music but have left little else in the history books. One is the Yazoo & Mississippi Valley Railroad, apparently absorbed into the ICRR in 1945 or 46. It was a successor line to the Yazoo & Delta which initials are one explanation for the title "Yellow Dog" applied to the line. The other explanation is that they were a non-union carrier who enforced a "Yellow Dog" contract on their employees. I am pretty sure that this carrier was the one that ran the passenger train disparagingly called the "Pea Vine" because it wound all over the Delta at about the speed that a pea vine grows.
The Southern Crossed the Dawg at Moorhead, Mississippi. The right angle intersection is still there, but at least one of the lines (the dawg) has been abandoned and the city of Moorhead built a water tank in the middle of it. The most likely candidate for the other line is the Columbus and Greenville, a line which claims to have been incorporated in 1975, but which has a United States Supreme Court case in 1943. Try as I might, I am unable to tie the C & G with the Southern RR.
Anybody out there real good with late nineteenth century railroad history? The anecdote which started this saying involves W.C. Handy waiting to catch a train to Memphis from Tutwiler, Mississippi in 1903 and hearing a song refrain from a fellow traveler who was going to "where the Southern cross the Dawg" i.e., Moorhead.