@timothy-gengarella Yes, an infantry unit is needed.
Fighting railroads cost?
In the Fighting Railroads expansion, rail costs $4, and $8 in the mountains. In the standard rulebook, rail costs $2, and $4 in the mountains. My guess was the rules changed, but the expansion rules have not been updated. This is important to know, because normally, the rules in expansions over rule the rulebook.
@captainnapalm Yes, go with the newer rules. Some of those early ones are very outdated.