Simplify the following text for a Grade 5 native English-speaking person.
Original: In the late 1970s , Mr. Magoo appeared in a new Saturday morning CBS television series called What 's New Mr. Magoo ?
Simplified: Mr. Quincy Magoo is a popular cartoon character from the late 1940s until the 1970s . Jim Backus was the voice of Mr. Magoo .