Miss Piggy has been pictured as the Statue of Liberty in many forms, including a Sigma Ceramics candlestick in the early 80's. Since that time, other such similar merchandise has been produced and she has gone on to appear as Lady Liberty in several on-screen and illustrated appearances.
A short comic in the Summer 1986 issue of Muppet Magazine tells the story of Lady Liberty's inspiration, Jeanne-Emilie Bartholdi as played by Miss Piggy. After cacthing a vase filled with flowers and a book titled "Theory of Flight," Bartholdi is instructed to stand in an awkward pose while a prototype is sculpted. The accompanying poster pull-out for the magazine is a photo of the result signed by Miss Piggy as "Miss Liberté."
Piggy appeared on screen as the Statue at the climax of Muppet*Vision 3D's closing number. She forms the centerpiece of the fountain outside the Muppet*Vision theater in Walt Disney World, and a number of Piggy items sold at the theme park have featured her in the Statue of Liberty costume.
The real Statue of Liberty appears in a MasterCard commercial with the Muppets, shot on location in New York, and had previously been seen with Kermit and Piggy in promotional material for The Muppets Take Manhattan.