In 1983 they changed it to settle a 12-year legal dispute. The case was filed because they were accused of copying characters and settings from Sid and Marty Krofft's H.R. Pufnstuf (compare H.R. with Mayor McCheese). After the verdict was reached they had to change some of their characters and themes. It's too bad, because McDonald's was a lot cooler before they started getting rid of the McDonaldLand characters--they used to tour and do live kids' shows with the McDonaldLand characters in my area, with a circus and everything. I also liked their Birthday Club where kids could get a free birthday party if they signed up.
(compare H.R. with Mayor McCheese)
I mean, not H.R. himself, but the mayor character on that show. Also the firemen characters and other characters.