Troops of the American Civil War were no exception. 3¢ postage would send a letter to a Union soldier; Confederates paid 5¢ (for up to 500 miles) at the beginning of the conflict, but 10¢ for all stamps after 1862. Letters that were forwarded because the army marched to a new encampment cost extra, and the soldiers on the receiving end had to pay for any postage due.
People wrote letters on lined paper and sealed them in 5 ½ by 3 inch envelopes that looked very much like those used today. Because letters were slipped into envelopes that could be glued shut, no one needed wax seals any more. And to dress up the mail, printers offered a slew of patriotic envelopes.
Most senders affixed the stamp in the standard upper right corner, but some either didn’t get that memo or wanted to send private messages via the language of stamps. According to one definition, an upside-down-stamp might mean “Do you remember me?”
Of course, no matter how decorated the envelope or how much postage cost, what concerned soldiers and their families back home the most was hearing from their loved ones, even if the news was heartbreaking.