Historyrecover, I see you're a brand-new member, so let me say "Welcome to TreasureNet's What-Is-It? forum, the best place on the internet to get unknown objects CORRECTLY identified."
US Army collar-disc insignia do not date as far back as the civil war. Dating Metallic Insignia: Collar Disks
To accurately time-date yours, we need a well-focused closeup photo of its back.
Your iron-backed anchor button is definitely a civilian-usage "Nautical-Motif" button made for use on civilian coats & jackets. Although its emblem is very similar to some European navy buttons, actual military navy buttons do not have an iron/steel back, because it will eventually make rust-stains on the uniform's cloth.