Rails are loved or hated by most birders. I definitely love them. So much so that I’m now working on my PhD studying them (among other things). Call me obsessed, here are a few of my favorite facts about rails. I’m going to define rails very broadly here, to include all members of Rallidae, since birds with rails in their common name aren’t unique from the other members of Rallidae and they are all fascinating.
The name ‘rail’ comes from the Norman word ‘raale’, meaning rattle. Probably related to the rattle-like call of the Water Rail (Rallus aquaticus).
Some rails can swim underwater. Sora (Porzana arolina) dive readily to dodge crazed researchers trying to catch them. Or at least my experience suggests they are. 
Some rails are game birds, though not all species or in all places. I haven’t yet had a chance to try rail, but I’m told it’s tasty. Rail hunting was a much bigger deal historically, but in recent decades has become less popular. It is often done with a specially trained dog who flushes the birds. Historically rails were hunted from boats where one person moved the boat along with a pole and the other actually hunted.
King Rails (Rallus elegans) are really interesting because part of the population migrates and part stays on the Gulf Coast year round. Though how exactly King and Clapper Rails (Rallus longirostris) should be defined as species is still very much up for debate.
Rails look like poor fliers when they fly. They are often seen dangling their feet and are rarely seen flying very far but many still manage to migrate long distances. Not all of them fly though; many species have become completely flightless, within our current suite of extant rail species and in those who have rather recently gone extinct.
My favorite flightless rail is the Inaccessible Island Rail (Atlantisia rogersi) , resident of Inaccessible Island (See map). They are the smallest flightless bird in the world! Thanks to a lack of constant human presence and no introduced predators they are doing quite well on their difficult to access island home. Remarkably we know more about Inaccessible Island Rails then many others, we even know how to measure it’s body to figure out it’s sex! 
Corn Crakes (Crex crex) learn the unique dialects of the other individuals around them and learn to imitate them back so they can maintain their territories! 
All species of bird in North America which have rail in their common name have been documented flying over the Gulf of Mexico during migration, not in huge numbers, but it does happen. 
Have any rail related questions? Hit me up on twitter! @amv_fournier
 Ripley, S.D., Olson, S.L. Rails of the World : A Monograph of the Family Rallidae http://books.google.com/books?id=Tk19fKZenlwC&lpg=PA3&ots=anHIsh_Eqg&dq=sora%20diving%20porzana&lr&pg=PA4#v=snippet&q=Sora%20diving&f=false
 Ryan, P. G., B. P. Watkins, and W. R. Siegfried. 1989. Morphometrics, Metabolic Rate and Body Temperature of the Smallest Flightless Bird : The Inaccessible Island Rail. The Condor 91:465–467. https://sora.unm.edu/sites/default/files/journals/condor/v091n02/p0465-p0467.pdf Ręk, P. 2013. Corncrake males learn new signal meanings during aggressive interactions. Animal Behaviour 86:451–457. http://www.sciencedirect.com/science/article/pii/S0003347213002637
 Russell, R. W. 2005. Interactions Between Migrating Birds and Offshore Oil and Gas Platforms in the Northern Gulf of Mexico Final Report Interactions Between Migrating Birds and Offshore Oil and Gas Platforms in the Northern Gulf of Mexico Final Report. Page 348. New Orleans, LA. http://www.data.boem.gov/PI/PDFImages/ESPIS/2/2955.pdf