MidAmericon was the name of the 34th World Science Fiction Convention (WorldCon). Also known as "Big Mac," the convention was a catalyst for the growth of science fiction fandom in a 4 state area and was the first WorldCon that many current con runners attended. Mid American Conventions, was not directly involved in Big Mac, but many MAC members participated in that convention and its heritage. 

In 2003 Mid American Conventions conducted an unsuccessfull bid to host a second Kansas City area WorldCon on the 30th  anniversary of the first. In 2006 Mid American Conventions conducted an unsuccessful second bid to host the WorldCon.

The third time was the charm and Kansas City hosted its second World Science Fiction Convention in 2016.