From the most basic materials, there will be a wide range of products you can manufacture and ship to towns. Keep the economy moving and keep the needs of the masses fulfilled.
Want to make some citizens happy with brand new cars? Great! You just need a factory, some engines, tires and frames. Where do you get that? Well, you're going to need some other factories to make it out of metal and rubber, right? Where do you get that? Maybe a refinery and some smelters and ... Well, you get the idea.