The build up of nuclear weapons since that’s what the whole Cold War was mostly about. Outbreaks of polio weren’t a huge concern since they were mostly in the earlier 20th century. The race to put men on space didn’t cause fear and didn’t pose a threat, and the invention of new computers were in the late 1900’s. Therefore the buildup of nuclear weapons was the biggest threat and concern.
When it was announced that Michigan would be applying for statehood as a free state, Sevier knew the abolitionists would have a numerical advantage in the U.S.
