Hi Alisha,
The Muppets: Great Moments in American History is such a fun show, featuring Sam the Eagle, Fozzie Bear, Kermit the Frog, Miss Piggy and more. I've seen it several times since it debuted in October and find it charming each time.
To the best of my knowledge, it is planned as a regular attraction at
Magic Kingdom. When it was
announced on the Disney Parks Blog, there was no mention of it being for a limited time. My best guess is that the schedule is being posted only a couple of weeks in advance.
It has been showing several times a day, from shortly after park opening until just before dark, since it debuted. Because you stand in Liberty Square and look up at the show (so there's no need to stand in a queue for a seat), it has been relatively easy to wander up a few minutes before each show and find a good viewing spot.
I'm hopeful you will find the show's schedule listed on the
Walt Disney World website soon, or at least in the Times Guide you will receive when you arrive.
Thanks for stopping by the Disney Parks Moms Panel, Alisha. Have a fabulous visit to Walt Disney World!
Wilma