To me, the American dream is the idea that anybody, no matter their background, can achieve anything with enough hard work and dedication. I think this concept is perfectly exemplified in the animated movie Ratatouille. 

At the start of the movie, the main character, Remy, is a rodent who feels bound to his family's expectations of him. According to them, he is supposed to be a thief who stuffs rotten food down his gullet and walks on all four paws. 

While squatting in an old woman's house, Remy watches his idol, Chef Auguste Gusteau, on television. Chef Gusteau repeats his catchphrase: "anyone can cook" which inspires Remy to chase his dreams. Chef Gusteau appears as a figment of Remy’s imagination, encouraging him to pursue success and stick to his morals when Remy is alone in Paris. While exploring the city, Remy finds bread while famished but resists the temptation to steal it, defying society's expectation of rats.

As Remy was peeking into Gusteau's restaurant, he fell and ended up saving a horrid soup with his culinary skills. The staff in the restaurant spot the busboy, Alfredo Linguini, tamper with the soup and assume he is the chef. Linguini is told to take Remy outside and kill him, but after witnessing Remy save the soup, they decide to work together. Remy controls Linguini by using his hair as a joystick. Thanks to Remy’s cooking skills, Linguini becomes a successful chef but is challenged by a mean critic, Anton Ego, who previously gave the restaurant a mediocre review that led to Chef Gusteau's death. 

Linguini admits to being controlled by a rat, and quite expectedly, the entire restaurant staff is shocked and leaves. Remy relays his rat colony to cook up a storm for the critic and all other customers. The rats all take proper sanitary precautions and create 5-star dishes; the methods were unconventional, but their end product was the same. Remy decides to make ratatouille for Ego; it is a peasant dish, but Remy understands that even things that come from humble beginnings are worthy of being plated in a 5-star restaurant if given enough care and attention. Well, the grumpy old critic loved the dish and gave the restaurant a stellar review, even after finding out a rat was the chef. At the end of the movie, Remy becomes head chef of a small yet successful bistro and enjoys the rest of his life.