Here is the full list of all 6 Civil War: Bull Run 1861 achievements.
Destroy 3 enemy units in a row without losing any of your own.
Destroy 8 enemy units in a row without losing any of your own.
Destroy 12 enemy units in a row without losing any of your own.
Complete the tutorial.
Complete 1 scenario on hard difficulty.
Complete 5 scenarios on Hard difficulty.