I never tried Sid Meier's Railroad Tycoon (though I was addicted Civilization I, II, and III). Fileshack is making the original Railroad Tycoon version available for free (15MB download).

Railroad Tycoon Released For Free

I haven't downloaded and tried this (I am somewhat cautious about registering at free download sites). However, for what it's worth, McAfee's SiteAdvisor gives the FileShack site a green checkmark.