socks, drawers, & undershirts
1861 - 1865
You are on your own to determine what you will wear for socks and underwear. We simply are never going to check.
If you choose to wear authentic cotton rag socks, or wool socks, you have our support. If you choose to wear modern socks, you have our support. Many of us wear our normal, everyday socks with our uniforms, particularly if they will not show (which is always the case when wearing boots). You should bear in mind, though, that period footwear may not feel the same as modern footwear, and may not be lined as so many of the better (and some of the worse) modern footwear is, which means that you may be wishing that you planned on wearing cotton rag or wool socks from the start. In the worst cases of poorly made period footwear, you may find yourself wishing you had worn the thicker period socks, and praying for death before your feet torture you further. Bear in mind also that deciding whether you will wear the thick reproduction socks or thin modern socks will affect how your footwear will fit. If your footwear is bought to fit modern socks on your feet, you may find it impossible to get your feet into the footwear if you later switch to the much-thicker period socks.
CS-issue socks fell into two categories: winter-weight and summer-weight. Wool socks are best for winter wear, and cotton socks, which are usually white or gray, are best suited for summer wear.
As for underwear, some of us elect to wear period underdrawers to protect us from the wool trousers, and the rest of us wear pajama bottoms or learn to live with the wool. Pajama bottoms are an excellent alternative to period underdrawers. Understand, however, that if you wear pajamas, you will need to take special care that your pajama bottoms are not exposed through the "V" in the back of your trousers waistband. That may be a compelling reason to have period underdrawers.
The undershirt is the old "long john" or "union suit" top, although there are also cotton undershirts patterned on period examples of such garments that you also may choose to wear. The modern Henley shirt is an acceptable substitute, and is readily available in most retail stores that sell clothing.
We would generally recommend against wearing modern undershirts, as the imprint of the undershirt through your shirt will reveal modern lines that don't square with the reproduction shirt you wear.