1. Origins of the Donkey and Elephant Symbols for Democrats and Republicans

2. Democrats - Symbol of a Donkey
The party itself never officially adopted this symbol but has made use of it.
They say Andrew Jackson had been labeled a jackass by his opponents during the intense mudslinging that occurred during the presidential race of A political cartoon titled "A Modern Balaam and his Ass" depicting Andrew Jackson riding and directing a donkey (representing the Democratic Party) was published in The cartoon was criticizing Jackson’s populist views.
A political cartoon by Thomas Nast in an 1870 edition of Harper's Weekly revived the donkey as a symbol for the Democratic Party. Cartoonists followed Nast and used the donkey to represent the Democrats, and the elephant to represent the Republicans.
Next page is Thomas Nast’s 1870 cartoon.

4. Republicans - Symbol of Elephant
“Grand Old Party”…
Used to be referred to as the Gallant Old Party until 1875
Origin of symbol:
Thomas Nast cartoon in Harper’s Weekly in 1874.
Ulysses S. Grant was contemplating running for a third term and was shown in a cartoon wearing a crown. This led Nast to criticize the Republican voters as foolish animals in a cartoon.
The cartoon had a donkey in a lion’s skin scaring away all the animals of the zoo. One of the animals was an elephant labeled “The Republican Vote”. This was based upon a fabricated story about animals escaping the zoo.

6. End Note
The Republicans claim the donkey is silly, stubborn. and ridiculous.
The Democrats say it is humble, courageous, and lovable.
The Democrats claim the elephant is stupid, pompous, and conservative.
The Republicans say it is a symbol of dignity, strength, and intelligence.