The similarities between jambalaya and the Spanish dish of paella are not too far apart. The term of "jambalaya" itself is derived from the Spanish word "jamón" (ham). The dish came into Creole cooking (which itself was influenced by French, Spanish, Italian, and German cuisine) sometime in the 1700s and started taking on some local influences in its ingredients.
Like most Creole dishes, jambalaya is essentially a "one pot" mix which includes rice, ham, chicken, shrimp, oysters, sausage, onion, garlic, peppers, and other seasonings. It's become one of the most ideal dishes for outdoor cooking and you're bound to see it at many outdoor festivals and political rallies in the Louisiana towns and cities.
It's been said that the Cajuns loved to cook and dine well because it brought a sense of reunion in spite of the tragedy of losing their land to the British. Jambalaya is the best example of that.