First Polio Epidemic
In 1894, the first recognized U.S. polio epidemic occurred in Vermont with 132 total cases (18 deaths), including several cases in adults.
References
Beaubien, Jason. "Wiping Out Polio: How the U.S. Snuffed Out a Killer." NPR All Things Considered, https://www.npr.org/sections/health-shots/2012/10/16/162670836/wiping-out-polio-how-the-u-s-snuffed-out-a-killer