"Subway tile is riding a wave of enormous popularity right now, but it's been around for a long time. If any of your walls are glazed with those ubiquitous 3" x 6" rectangles, you have a little piece of history in your home. It will probably not come as much of a shock that subway tile was originally designed to be placed in subways. Designers George C. Heins and Christopher Grant La Farge created the distinctive 3" x 6" rectangles for the very first station of New York's then brand-new subway in 1904."
"The Victorians, you see, were obsessed with hygiene, and one advantage of tiles was that they didn't stain and were easy to clean. This is, of course, a bit ironic considering that lots of people nowadays think subway tile is 'dirty', precisely because they associate it with the subway. But for turn of the century New Yorkers, to whom underground transportation was a brand new concept, all that shiny tile read as spic and span. The white tile had the additional advantage of reflecting light, brightening the subterranean stations."
"Following the debut of the tile in the subway, it began to appear in all kinds of interiors: bathrooms, kitchens, butcher shops — any place you would want to be especially clean. (Keep in mind, this was before the subway's 70s - 80s nadir, so the idea of the subway as a scummy, rat-filled underground hole hadn't yet entered the collective consciousness.)"
"Now subway tile is back in a big way (although the argument can be made that it never really went away — although it wasn't nearly as popular then, it still occasionally crops up in photos of 70s and 80s kitchens). It's usually laid in the traditional brick pattern, although there are all kinds of variations).
It's possible that there's a little bit of nostalgia in our current embrace of subway tile — it seems to speak to an easier, more elegant time, and it's also a great fit for the kind of new kitchens, made to look old, that are so popular right now. However you decide to use it, subway tile is inexpensive, versatile, and, as we've seen, has a great pedigree."
Source: Apartment Therapy