If you’re trying to find all the rare plans in Fallout 76 then you’ll want to check out the video above! The video provides a great simple tutorial on where the Confederate Uniform Plan is located on the map. The confederate uniform plan is part of the random encounters you’ll find across the map. You may have to jump servers a few times inorder to have the confederate uniform plan to spawn.
Here is a great post about the other rare plans to search for in Fallout 76. Some of the are part of the random encounters like the confederate uniform plan.