About 1833NE, from BoardGameGeek:
1833NE (called 1834 in prototype) is an 18xx game set in the Northeastern United States. The scale is significantly smaller than many 18xx games and depicts regional railroading, where constantly changing outside forces buffet the players. 1833NE includes both standard and takeover versions.
The standard game is most like 1846 (and therefore has a linear stock market, multiple types of trains available at each phase, and paying for most track lays), but adds ferries, small cities, and interconnection bonuses, as well as using an auction -- not a draft -- to distribute the private companies.
The takeover game adds 5 variable start railroads and takeovers, by which one railroad can acquire another one, increasing its train limit (which is reduced from the standard game).
As a bonus, 1833NE includes 1846: The Race for the Midwest - Mini-Expansion (included in second edition 1846) for first edition 1846 owners.
