Early Americans preferred their eggnog with rum, reveling that bargain shoppers existed long before Walmart. Rum was much cheaper than other alcohol during colonial days because of the Triangle Trade with the Caribbean (wine and other alcohol from across the Pacific was heavily taxed).
Eggnog is a drink consisting of egg yolk, cream or milk and sugar. Add whiskey, rum or another liquor if you like. It’s name comes from the combination of egg (duh) and nog meaning a strong type of beer in the language of our English language forefathers. A noggin back then was a wooden cup that nog was drunk from (bonus material). Eggnog in French is lait de poule or hen’s milk.
Go forth and be merry now.