By contrast in the 1950's fewer than 2% of the population held stock in a U.S. corporation.
When I was growing up we had one car titled in my father's name. So strictly speaking only 25% of the family population owned a car. But 100% of the family population accrued benefit from car ownership.
Likewise with slavery. Virtually all of that 5% of the population were married, so suddenly your 5% becomes 10% who draw direct benefit from slavery. Those 10% likely had children so suddenly your 10% becomes 15% or 20% or 25%.
A better indicator of how important slavery is would be the number of families in the south which were slave owners. In 1860 that reached a high of almost 50% of the families in Mississippi. Throughout the original 7 Confederate states I believe the percentage was in the mid-30s.
...concerned about the exorbitant price of goods needed from the north...Prices set by the taxes and tariffs instilled by the industrial north...
You are aware that those tariffs impacted the Northern consumers just as badly as Southern consumers? So if tariffs were worth rebelling over in the South why weren't they worth rebelling over in the North?
“...You are aware that those tariffs impacted the Northern consumers just as badly as Southern consumers?...”
No, not really...Those taxes and tariffs were placed on goods the south bought from Europe in trade with their cotton...The north already had those industrial products and charged the south MORE for them than did Europe...The north placed the tariffs to cause the European products to be too costly for the south and forced the south to get them from the north...At HIGHER prices...