When I was very young, I would stay with my grandmother. Grandfather ran his own business and Grandmother always got anxious when the mailman was due. There could be a check in the mail.
Back then the mailman came twice a day. Once in the morning and again around 3 o’clock.
In the 1850s there were not that many telephones, no radios, and telegrams were very expensive. You had to go see someone in person or send them a letter. You could send a letter in the morning to invite someone to tea and get a response that they would be coming well before tea time.
I haven’t seen a story that implies that the mail was prompt and delivered several times a day. Also there were messengers, professional messengers, not just any old person off the street.
How could they afford to deliver mail twice a day. Estimates for how much a 1850 dollars could buy today range from 33.33 dollars to 4000.00 dollars. I recently saw an inflation article that stated that a dollar in 2014 could only buy $0.13 in 1965. So I feel that a dollar today may be worth 1/2000th of a 1850’s dollar. That’s half way between the $33.00 and $4000.00 estimate. So a penny postcard would cost a dollar of today’s money or several dollars in today’s money.
Don’t forget that train service was good in the past and the mail traveled by train. Mail traveling by ship could take several days but it could beat a messenger.
People that lived before cell phones and telephones could and did communicate, some times weekly or even daily. Without telephones letter writing was the only way to communicate long distances and people took letter writing seriously.
Your story should take letter writing seriously.
Stay strong, write on, write a letter today. Professor Hyram Voltage.