Here is the full list of all 50 The History Channel: Civil War - there are A Nation Divided achievements worth 1,000 gamerscore.
The war has just started.
Tactical skill and deadly aim, you are well known in your regiment.
Your name brings fear into the hearts of your enemies.
You are an inspiration for your men.
In a fight man against man, there is no match for you.
You have successfully survived the greatest conflicts of the Civil War.
You have survived the battle of Fredericksburg.
Your aim is precise, and your skills are deadly.
One shot, one kill. No one has a chance against you.
You have survived the battle of Gettysburg.
You have survived the battle of Chattanooga.
You have survived the battle of Fort Fisher.
You have survived the battle of Selma.
You have survived the battle of Petersburg.
You have survived the battle of Bull Run.
You have survived the battle of Shiloh.
You have survived the battle of Antietam.
You have survived the battle of Chancellorsville.
You have survived the battle of Chickamauga.
You have survived the battle of Cold Harbor.
To earn this award you must kill 750 of your enemies.
To earn this award you must kill 100 of your enemies with your pistol.
To earn this award you must kill 75 of your enemies with your knife.
Complete the game on the Normal (or higher) difficulty setting.
Complete the game on the Hard difficulty setting.
To earn this award you must find all secret photographs in the game.
To earn this award you must find all secret documents in the game.
Complete the Petersburg mission with an accuracy above 95%.
Complete the Bull Run mission with an accuracy above 95%.
Complete the Antietam mission with an accuracy above 95%.
Complete the Chickamauga mission with an accuracy above 95%.
Complete the Cold Harbor mission with an accuracy above 95%.