Back in the 1860s, repeating rifles were a pretty new development. There was a still a lot of horse-riding and open field-fighting. And the Ashokan Farewell played under everything. But the south had a high tech trick under its sleeve. A good old-fashioned whirlybird.
Developed by engineer William C. Powers, who lived in Mobile Alabama, this 1860s beast was intended to fly over the Union Navy and give them a pummelling Confederate ships just couldn't pull off. Like the concept of Da Vinci fame, the airship would have relied on Archimedean screws (four, in fact) to provide lift and thrust, with a rudder for steering
The idea was plagued with problems though, from the lack of a thorough understanding of aerodynamics to the absence of an engine powerful enough to take it off the ground. As such it never made it past model form. The National Air and Space Museum has more on the 'copter, including some of the early plans. You now excused to go write your historical fiction. [The National Air and Space Museum via Slate]