Based on reports from that era, the tribe was highly secretive and suspicious of outsiders long before this event happened. The first time a Westerner recorded encountering the island, they mentioned seeing signs of recent habitation, but finding no inhabitants, as if they had disappeared into the forest. Likely, they just didn't want to interact with strange intruders in their territory.

The US Civil War still has a very large impact on the culture of the South.

A single event that affects 3% or more of the entire population is pretty memorable.