Empress' Crusade. American Imperium Trilogy

Faustina Hartmann has led her army from Huntsville to Vicksburg, across the desolated Old South, to secure a rail line to allow her hometown, Knoxville, access to the uranium ore they so badly need. At the end of a thin, 400-mile supply line, she suddenly finds herself set upon by adversaries to the north and south, potentially cutting off and destroying her men. Taking swift action, Faustina rallies her four legions and leads them into battle.
A battle fought not only on the ground but also in the Void, where her demi-human modifications and her alliances with Thinking Machines can be brought to bear. Long marches, bloody battles, but also clever diplomacy and even a hint of romance await Faustina as she continues her crusade to create her personal empire in the old US Deep South.