Where did the symbols of the donkey and elephant for the two political parties of the US originate?

The Democratic Party’s donkey can be traced back to the 1828 presidential campaign of Andrew Jackson, whose opponents referred to him as a “jackass.” Jackson embraced the image and featured the donkey on his campaign posters. Years later, a political cartoonist named Thomas Nast helped popularize the donkey as a symbol for the whole Democratic Party.

Nast was also responsible for promoting the elephant as a symbol for the Republican Party. He first used it in an 1874 drawing titled “The Third-Term Panic” featuring an elephant labeled “The Republican vote.” He continued to use the elephant as a symbol for the party, and other cartoonists followed suit, cementing the association.