You're headed off in the worng direction.
One of the great changes that took place during the 1850s was the advent of mass media. The telegraph allowed information to move over the wires at unheard of speeds, so that news that formerly had taken days or weeks to reach distant locations could be reported overnight.
Not everyone could read a newspaper, but it's hard to imagine that any white citizen in the United States didn't talk with people who did read newspapers. An Alabama newspaper which conducted a survey in 1860 of all newspapers in the state listed just short of ninety publications. Some were weekly, but most were daily, and they could be found in almost every county of the state.
The ratio of newspapers to state population in 1860 was much higher than it is today. Also, people were far more likely to believe what they read uncritically at that time, so the role of the opinion-maker in 1860 was even greater than today.
You must remember that people had little besides routine tasks to occupy their attention. Especially with the great issues of the day before the people, no one would miss a political rally in 1860. These were great social events, also.