Aptly named, St. Patrick's day celebrates St. Patrick, the patron saint of Ireland. Patrick was born in the Roman empire in the 4th century and was kidnapped at the age of 16 and brought to Ireland. He escaped Ireland but later returned to convert the Irish people to Christianity in 432 CE. St. Patrick died on March 17, 461; he established monasteries, churches, and schools across Ireland. Many legends are attributed to him, such as using a clover to explain the trinity and driving all snakes out of Ireland.
The more secular holiday we know today was brought to the US from Irish immigrants. Large cities were often home to many Irish Americans, and they often held political power in these cities. They would stage elaborate celebrations, with the first designated parade by held in Boston in 1737. Since then, St. Patrick's day has become a holiday of revelry and merriment, celebrating all things Irish. From musical festivals to draft beer, green outfits to special sports games, St. Patrick's day has something for everyone!