NANTUCKET, Mass. — An African-American historic site has been vandalized with racist graffiti.The outside of the 19th century African Meeting House in Nantucket was spray-painted with racist and sexually explicit slurs.The Nantucket Police Department is investigating the incident, and gathered evidence before dozens of community members scrubbed the paint off the front door on Sunday morning.The director of the African meeting house Charity-Grace Mofsen told the Cape Cod Times , "I broke down," as she reacted to seeing the graffiti.