Horsepower: 5000 Expansion Set 1 – World Rails

From the cover card:

This set contains 90 High-Resolution Laser Printed Game Cards that you can customize into your own playing deck. Use your deck to outwit the other players and build an Empire! Requires a Starter Set or a Deluxe Set to play.

Expands

Horsepower: 5000 Deluxe Set 1 - Northern Iron