1843 aka 18FR-RCE, more familiarly known as 18Fried Rice, is an 18xx re-envisioning of 18FR. Significant differences include a ninth company, an extended train roster, a slew of map changes, an additional private company with a new power and tweaks to the other privates, changes to the track-tile manifest, etc.
The primary goals of 1843 were to reduce the bankruptcy rate to well below 50% of games (versus the near 100% rate of 1830 and 18FR when played aggressively, while also providing for more interesting train and track management sub-games (especially in the late game).