Here is a quick and simple guide on where to find the Civil War Knife and Hat in Red Dead Redemption 2.
Step 1 - Head to the Fort
First off head to the old broken down Fort, known as Fort Brennand. This is located on the East side of Emerald Station. We have pinpointed it below.
Step 2 - Head inside the Fort
Head inside the Fort, there is plenty of ways in, then go over to the old Cabin which has some sort of Lava next to it.
Step 3 - Collect the Civil War Hat
When inside the Cabin, find the ladders leading to the Basement. When you go down them, you'll find the Civil War Hat located in front of you
Step 4 - Collect the Civil War Knife
Once you have collected the Hat, look behind you and the Knife is locatred on a set of Crates.
Step 5 - Enjoy
That is everything you need to do to find the Civil war Hat and Knife. When you're leaving watch out for Rattle Snakes.