The Americanization of St. Patrick's Day

<p>In Ireland, <a href="https://twitter.com/hashtag/StPatricksDay?src=hash">#StPatricksDay</a> was just a minor religious holiday for centuries — and not one that involved drinking. Then Americans appropriated it in the 1960s and now we have the <a href="https://twitter.com/hashtag/shamrockshake?src=hash">#shamrockshake</a>.&nbsp;</p>