At the risk of hijacking your thread, I wanted to share a brief passage about the Zouave button you found and how it relates to my finds in Wisconsin. I have found a couple of those buttons and this helps tie it together!
From Wikipedia:
Zouaves gradually vanished from the U.S. military in the 1870s and 1880s, as the militia system slowly transformed into the National Guard. As an example, the Wisconsin militia still included one zouave unit in 1879. Unfortunately, the following year, in 1880, a standard Wisconsin Guard uniform was adopted, and the traditional distinctions of title and dress ceased.[37] After the Civil War, veteran groups sometimes dressed as zouaves during honor guard ceremonies such as funeral processions, since zouave dress was considered colorful and distinctive. Modern American Civil War reenactments often feature zouave units.[38]
