It is primarily celebrated as recognition of Irish and Irish American culture; celebrations include prominent displays of the color green, eating and drinking, religious observances, and numerous parades. Though the St. Patrick’s Day parade is now a tangible effect of Worcester’s Irish immigration, the ethnic group was not always a welcomed addition to the city’s cultural landscape. Irish Immigrants faced political, social and economic discrimination. It was not until the construction of the Blackstone Valley canal and first Irish Catholic mayor, Philip J. O’Donnell was elected in 1901. Catholic churches, cemeteries, schools, neighborhoods and social organizations reflected and continue to reflect a large immigrant presence in Worcester, an immigrant presence that transformed the agricultural town of Worcester into an industrial and urban powerhouse and one that nearly one-third of city residents still claim ancestry.