You may not have realized it, but you will be commemorating over 1500 years of history as you don your green and taste that corned beef and cabbage. However, the holiday has not always included elements from today's festivities, including the "wearin' of the green" and the corned beef and cabbage.
The St. Patrick's Day parade itself actually got its start in the city of Boston only several hundred years ago in 1737 (just recent history in the timeline of the Irish). Perhaps the biggest parade of them all, in New York City, had its first run in 1762.
St. Patrick himself was born way back in the 4th century. For a little bit more history on the day that bears his name, view the History Channel's three-minute video History of the Holidays: St. Patrick's Day. It gives an introduction to St. Patrick's life, explains the origin of his feast day and also covers the modern interpretion of it via parades and corned beef and cabbage.
As the video explains, the corned beef tradition is an Irish-American invention: the meat served as a cheap substitute for traditional ingredients that weren't as readily available in the United States.
If you can't get enough of St. Patrick's Day, take a tour of more of the History Channel's St. Patrick's Day minisite or Biography.com's Celebrating St. Patrick & the Irish website.
Also take a look at The Wearing of the Green: History of St. Patrick's Day by Daryl Adair and Mike Cronin. It is a book for all serious lovers of history who wear their green on March 17.
For a look at the history of the traditional celebrations in Ireland itself, see the Irish Culture & Customs article by Bridget Haggerty entitled Celebrating St. Patrick's Day in Old Ireland.
Here's wishing you...