Ask SAM: St. Patrick's Day is Friday. Here's a little history of the holiday.

St. Patrick’s Day has been observed for more than 1,000 years, according to History.com. Patrick was born in Britain in the fifth century, when it was under Roman rule. When he was 16 years old, he was captured and taken to Ireland as a slave.

He escaped, but returned in 432 A.D. to bring Christianity to Ireland, according to Britannica.com. He started churches, schools and monasteries. There are also many legends associated with Patrick. One of the best known is that he drove the snakes out of Ireland.

According to the legend, Patrick was preaching a sermon that caused the snakes to slither into the sea, said History.com. But scholars say that the snakes in the legend are actually a metaphor for pagan rituals.

St. Patrick’s Day commemorates Patrick’s death, believed to be March 17, 461. The Irish began observing the Feast Day of St. Patrick on March 17 in about the ninth or tenth century.

The first St. Patrick’s Day parade wasn’t held in Ireland, but in the Spanish colony of St. Augustine, in present day Florida. The colony had an Irish priest.

In 1772 Irish troops serving in the British army in New York City had a parade to honor St. Patrick and the tradition began to grow among Americans in New York, Boston and other American cities.

The St. Patrick’s Day parade in New York City was formed in 1848 when several Irish groups pulled together to have one parade. It’s the largest parade in the world, with more than 150,000 people taking part. More than 3 million people line the parade route. It is also “the world’s oldest civilian parade,” according to History.com.

In addition to New York City, St. Patrick Day parades are also held in Boston, Chicago, Philadelphia, and Savannah. In Chicago green dye is used to turn the Chicago River green. In the early 1960s, Savannah tried to dye the Savannah River green, but the color didn’t work well and the city decided not to try again.

St. Patrick’s Day traditions

For many in the United States the day has become a time celebrate all things Irish. Many people will have corned beef and cabbage, while wearing a green shirt and listening to Irish music. After they eat, they may work off the calories by doing some Irish dancing.

While cabbage was eaten in Ireland, corned beef was not traditionally an Irish meat. In the early 20th century, Irish immigrants living in New York City substituted corned beef for the more expensive Irish bacon, which with cabbage, was a traditional Irish meal. The Irish learned about corned beef from their Jewish neighbors.

The shamrock became associated with the day when, as legend has it, St. Patrick used the leaves of the shamrock to explain the Holy Trinity.

Although blue was originally associated with St. Patrick, green has become the color most people associate with the day. It began with Irish Catholics wearing a shamrock in their lapel on St. Patrick’s Day. Later they wore green clothing to identify as a Catholic after the Irish uprising against British rule in the late 1700s. In the United States, many people wear green on March 17 to show support for the Irish.