I was browsing the net the other day and happened on a wonderful site with great advice for folks who want authenticity in recreating civil war era fashion. I think the site is mostly used by civil war enactors.
Here’s a quote on use of buttons for the era.
Button use will really depend on the garment; flat trouser buttons work for trousers, but you’d be more likely to see four-hole white china buttons (sometimes called “milk glass”) on a boy’s white shirt or underdrawers, or white or calico buttons (color-patterned with a tiny design) on a boy’s print shirt, for instance. A boy’s wool coat might use a self-fabric covered button, or even (non-military) molded metal buttons. So it all depends on the garment and its use, as well as the economic level of the family. For girls, look at white four-hole buttons for undergarments (petticoats, drawers). White china seem to be the most common for those garments, and four-hole buttons can be stitched on securely making an X in front and a square on the back, which is very strong and stable (instructions are included in the pattern booklets). For dresses, I’ve yet to see any girl’s dress from the period that uses carved wooden buttons myself, or any notes that recommend them. This makes sense once you take into account laundry methods: wooden buttons do not long survive a cycle of boiling and scrubbing! They dry out and crack and crumble. The most common buttons for girl’s everyday cotton dresses seem to be the plain or patterned china buttons, quite small (under 1/2″), and fairly numerous (every inch or so). That’s *IF* buttons are used as the back closure; another totally valid option is closing a girl’s dress with hooks and eyes (not bars) down the back, which makes them a bit more flexible, size-wise, as you don’t have to cut permanent holes into the back placket to set hooks, as you do with buttons. I’d avoid wooden and most metal buttons for girl’s dresses. Small mother-of-pearl buttons can work (from 3/8″ to just less than 1/2″); avoid anything plastic looking, which generally rules out most of the button selection in my town…. which is why I tend to opt for hooks/eyes for my own girls. Ebay can be a good spot for button purchases sometimes, though you’re bidding against collectors in many cases. Vintage store stock of some of the basic calico or white china buttons are quite sturdy, so long as you don’t send them through a modern dryer (gets them hot, and makes them more brittle.) If you’re having trouble finding suitable buttons, just go with a #2 or #3 hook and eye. One exception to the “no wooden buttons” idea is the seed button–but that’s not a generalized item, and fits with late-war Southern Blockade ersatz scenarios, not into generalized norms for girl’s dress closures mid-century.