Before the development of railways in the Gulf states, Apalachicola was the third busiest port in the Gulf of Mexico (behind New Orleans and Mobile). The port brought wealth and a diverse population, building the foundation for a great city. The original city plan, laid with wide streets and squares, was modeled after Philadelphia and is still intact today. In the late 1800s and early 1900s, the sponge trade, led by Greek immigrants, was a major industry. After the turn of the 20th century, Apalachicola reinvented itself as the home to wealthy lumber barons. Seafood has always been a staple of life, and still today, the city boasts a working waterfront for a variety of seafood workers, including oyster harvesters and shrimpers.