According to Britannica “St. Patrick’s Day is celebrated on March 17, the feast day of St. Patrick, the patron saint of Ireland. St. Patrick was born in Roman Britain in the late 4th century and was kidnapped at the age of 16, taken to Ireland as a slave. He later escaped but returned to Ireland around 432 CE to convert the Irish to Christianity. By the time of his death on March 17, 461, he had established numerous monasteries, churches, and schools. Several legends are associated with him, such as driving snakes out of Ireland and using the shamrock to explain the Trinity.

Originally, St. Patrick’s Day was celebrated in Ireland with religious services and feasts. However, it was Irish emigrants, particularly in the United States, who transformed it into a largely secular holiday celebrating Irish culture. Cities with significant Irish immigrant populations, like Boston and New York City, began holding elaborate parades, with Boston’s first parade in 1737 and New York City’s in 1762. Chicago has been coloring its river green since 1962 to mark the holiday. While blue was traditionally associated with St. Patrick, green is now the color most commonly connected with the day. Celebrations often include wearing green, displaying shamrocks, and enjoying Irish foods like corned beef and cabbage.”