Complex sentence: Kelly was elected president of the National Cartoonists Society in 1954, serving until 1956, and was also the first strip cartoonist to be invited to contribute originals to the Library of Congress.
Split into simpler sentences: Kelly was elected president of the National Cartoonists Society in 1954, serving until 1956. He was the first strip cartoonist to be invited to contribute originals to the Library of Congress.