I think Tennessee has the record for "Official" state songs. It seems as though everytime some Tennessee ditty comes along, the legislature makes it an "Official State Song." I think they are now at SIX!!!
1) My Homeland Tennessee -date adopted not known
2) When It's Iris Time in Tennessee - 1935
3) My Tennessee - 1955
4) Tennessee Waltz - 1965 (not surprising and most recognized)
5) Rocky Top - 1982 (they'll take anything)
6) Tennessee - 1992