St. Dominic's Church was dedicated in 1893 and replaced a building constructed in 1830 as the first Catholic church in Portland. Originally, lay women were most active in such women's groups as the Altar Society, and women and girls later integrated into church life as Eucharistic ministers and altar girls. The school, which opened for girls in 1865, was originally operated by the Sisters of Notre Dame. It was taken over by the Sisters of Mercy in 1873, when the church decided that boys and girls could be taught together in the primary grades. The Notre Dame Sisters returned to Canada, because their order only allowed them to teach girls. The Diocese closed the school in 1973, and the Diocese of Portland closed the church, the third oldest Catholic church in Maine and home to the largest Irish Catholic parish north of Boston, in 1997. The city purchased it and gifted the building to the Irish American Club and Friends of St. Dominic's in 2003. The renovated church reopened in October, 2008 as the Maine Irish Heritage Center to provide a meeting place for Maine's diverse communities and promote Irish culture, history and heritage.