"St. Patrick is said to have used the three-leaved plant to explain the Holy Trinity (Father, Son, and Holy Spirit) to the pagan Irish."iStock

St. Patrick’s Day is the one day a year where everyone is a little bit Irish but how much do you know about the day?

St. Patrick’s Day is the one day a year where everyone is a little bit Irish. In fact, almost 12 percent of Americans claim Irish ancestry and over 80 million people worldwide claim an ancestral connection to the auld sod. With St. Patrick’s Day celebrated across the world, did you ever wonder how much you actually know about Ireland’s biggest national holiday?

Here are our ten top facts about St. Patrick's Day. Let us know how well you do in the comments section!

St. Patrick was not Irish

He was from Wales.

Getty Images

Getty Images

The shamrock was originally a teaching tool

St. Patrick is said to have used the three-leaved plant to explain the Holy Trinity (Father, Son, and Holy Spirit) to the pagan Irish.

First St. Patrick's Day parade

The first St. Patrick’s Day parade took place in New York in the 1760s.

Wear blue on St. Patrick's Day

For many years, blue was the color most often associated with St. Patrick. Green was considered unlucky. St. Patrick’s blue was considered symbolic of Ireland for many centuries and the Irish Presidential Standard is still blue.

Garry Knight/Flickr

Garry Knight/Flickr

Worlds shortest St. Patrick's Day parade

For many years, Dripsey in County Cork had the world’s shortest parade, just 77 feet, the distance between two pubs – The Weigh Inn and The Lee Valley. Currently, the town of Hot Springs, Arkansas, claims to have the shortest parade – a 98-foot route on Bridge Street. Recent participants included the Irish Elvises and the San Diego Chicken.

Over 200 years in Sydney

In 2010, the Sydney Opera House went green to mark the 200th anniversary of St. Patrick’s Day there. In Sydney, St Patrick’s Day was first marked in 1810, when Lachlan Macquarie, the Governor of New South Wales, provided entertainment for Irish convict workers.

The Chicago green river

In Chicago every year, the Plumbers Local 110 union dyes the river “Kelly” green. The dye lasts for about five hours.

Getty Images

Getty Images

Shamrocks at the White House

Traditionally, every year, the Irish leader hands a crystal bowl full of shamrock to the US President. The shamrock, grown in Kerry, is immediately destroyed by the Secret Service after the exchange.

Guinness sales St. Patrick's Day

Guinness sales soar on St. Patrick’s Day. Recent figures show that 5.5 million pints of the black stuff are downed around the world every day. On St. Patrick’s Day that figure is doubled.

* Originally published in February 2012.