In honor of Ireland's patron saint, March 17th (the day Saint Patrick is believed to have died) is celebrated anually as St. Patrick's Day. At the age of 16, Patrick was kidnapped and sold into slavery in Ireland. During his six years in captivity, he worked as a shepherd and began to have religious visions. During one of the visions, Patrick became aware of a rescue ship and he fled to France.Eventually returning to Ireland as a missionary, Patrick succeeded in converting the Irish to Christianity using the shamrock to explain the Trinity - the three leaves of the shamrock represented the Father, Son, and Holy Spirit.
Boston held its first St. Patrick's Day parade in 1737. St. Patrick's Day is celebrated with green beer, the wearing of green clothing and parades. However, in Ireland, the day is primarily a religious occasion.
Because many Americans celebrate their Irish lineage on St. Patrick's Day, March was chosen as Irish-American Heritage Month, first proclaimed in 1995 by Congress.