This is an idea I came up with that might initially seem complicated, but it's pretty simple.  Overtime, however, a network of intricate supply chains and relationships may develop.

The setting would be late-19th century North America, with the potential to include other locations later.  Each player creates a character who is the owner of some type of business.  You will work together to create [i]Ventures[/i], which increases your wealth every season, which is then used to create more ventures.  I will provide a basic example below:

Player1 owns a mining industry; player2 owns a locomotive company; player3 owns a steel mill in Chicago.  All three players decide to create a Venture where a railroad is built to transport the iron from the mine to the steel mill in Chicago.  It's a pretty basic supply chain, and each involved party increases the wealth of the venture by $100,000 - so this venture is worth $300,000 per season.  Your characters will need to decide how to divide up the profits; the fairest thing to do is to split it evenly - but that doesn't always have to be the case.

Over time other ventures can be made.  A supply chain involving the transport of bananas from Latin America to the United States, for example.  Perhaps another player wants to join an existing venture: a weapons manufacturer buying steel from the Chicago mill?  Maybe another player wants to smuggle those weapons to another country.  The ideas are endless - but it's all about production and transport and combining your occupations to get it done.  You can even attempt to take someone's spot in a venture by offering a better deal.

After a little while a new season begins: time passes, your wealth increases, new opportunities arise, and if the player's are interested we can create storylines.  A storyline might concern a city riot that ruins a business, or a union strike, or a foreign war, etc - the outcomes of which are determined by the involvement and investment of the players.

I would want to aim to create an intricate web of supply chains and logistic networks, while doing the same thing with character relationships!

What do you think of this idea - and would you like to try it out?