Petoria existed within the state of Rhode Island, America. It was only two meters long and was located on Spooner Street. It began when Peter Griffin, former President of Petoria, discovered his home and the surrounding area were not part of Rhode Island, or even the USA. He immediately declared his home to be a country and began to allie himself with terrosrist countries such as Afghanistan, and became the friend of such dictators as Moammar Gadhafi. He became to copy the actions of his terrorist friends and declared war on the US by conquering Joe Swanson's pool.
The United States did not take kindly to this and immediately prepared a nuclear assault. President Griffin surrendered, and was brought to the White House to have peace talks with President Clinton. As a result of his actions President Griffin was forced to join his once proud country with the United States.
Among the prominent works of Petoria while it existed were it's space program and many works of art.
The Petorian Space Program consisted of Chris Griffin, director of the PSP, climbing the only tree in Petoria and stretching his arm in the direction of the moon. As far as we know, the effort failed miserably.