Complex sentence: Dan Reilly was the first person to wear the Mr. Met costume, starting in 1964, but in the early 1970s, the Met franchise removed Mr. Met from action for close to 20 years.
Split into simpler sentences: Dan Reilly was the first person to wear the Mr. Met costume, starting in 1964. In the mid 1970s, the Met franchise removed Mr. Met from action for almost 20 years.