Tennessee raised 59 Union Regiments. Nashville was in Union hands from very early in the war. Andrew Johnson was governor his son Robert was Lt Col in the 1st Tn Cav US eventually posted for a time in Nashville. The city became safe-haven for numerous southern born Unionists. Try EAST TENNESSEE IN THE CIVIL WAR by O P Temple and HISTORY of the FIRST REGIMENT of TENNESSEE VOLUNTEER CAVALRY by W R Carter. Both books from Overmountain Press.