A cartoon by Thomas Nast titled "A Live Jackass Kicking a Dead Lion" appeared 
the January 15, 1870 issue of "Harper’s Weekly." The cartoon used the donkey to symbolize the Democratic Party for the first time.

Thomas H. Nast, "Father of the American Cartoon"

Snoopy, Charlie Brown, Linus, Lucy and Woodstock of Charles Schulz’ "Peanuts" comic strip.

Walter Elias "Walt" Disney (December 5, 1901 – December 15, 1966)  

Ramblin’ Rod Anders  (November 26, 1933 – May 11, 2002)

Born Rodney Carl Andersen, Rod was the host of The Ramblin’ Rod Show, a 
children’s television program on Portland, Oregon’s KPTV Ch. 12, from 1964
until his retirement on August 8, 1997. He was well known for his message 
button-covered sweater (above). At the time of his death, Anders had
collected over 25,000 buttons which were given to him by adoring fans
and many guests of his TV show. He is missed by many.

Aired on KPTV, January 30, 1981

The traditional mascot of the Republican party is the elephant. A political cartoon (above) by Thomas Nast, published in Harpers Weekly on November 7, 1874, is considered the first notable appearance  of the symbol.

Thomas Nast is Considered the father of American
political cartooning.

 
Harpers Weekly, 11-7-1874