Simplify the following text for a Grade 6 native English-speaking person.
Original: The present corporation dates its founding to the opening of a franchised restaurant by Ray Kroc , in Des Plaines , Illinois , on April 15 , 1955 , the ninth McDonald 's restaurant overall .
Simplified: McDonald 's has been around since 1955 , when it was started by Ray Kroc in Des Plaines , Illinois .