(written from a Production point of view)
Southworth was born in Lancashire, England, but moved to the United States after receiving a scholarship from the Chicago Art Institute. He began working in the animation department at Walt Disney Studios in 1944, where he took part in such films as Cinderella and Alice in Wonderland. He moved on to Hanna-Barbera, where he spent 21 years. During this time, he animated such shows as The Flintstones, The Yogi Bear Show, Huckleberry Hound, Top Cat, Scooby-Doo, Where Are You!, and Smurfs.
Southworth died in Anaheim, California after suffering multiple strokes. He was 89 years old.