Henrietta, NY: possibly consumption (tuberculosis)
Lewiston, Maine, originally called Lewistown, was named and settled years before Meriwether Lewis became famous. It’s probably named for Job Lewis, a Boston businessman. I have no idea how Job died.
Interestingly, the best known Alexandrias in the US were not named (ostensibly) after Alexandria, Egypt, and hence after Alexander the Great (who died of malaria, typhoid, poison, or something else). Alexandria, Virginia, was named after the Alexander family, Alexandria, Louisiana after founder Alexander Fulton, and Alexandria, Minnesota after early settler Alexander Kinkead. I haven’t found causes of death of any of them. Of course, the form of the name is based on the city in Egypt, but they commemorate people other than Alexander the Great.
Arrow shirt?
Lexington Park, MD: Gunshot wounds (multiple torpedoes and surface gunnery)
Franklin, Tennessee: pleurisy
Hamilton, Kansas: fatally wounded in a duel
Polk, Wisconsin: cholera
Harrison, Ohio: pneumonia, jaundice, and septicemia
Fillmore, New York: stroke
Rough and Ready, California (Zachary Taylor): dysentery
Randolph MA: apoplexy.
And thanks to bibliophage for the Lewiston ME info.