The Raritan Bay Union was a utopian community in Perth Amboy, New Jersey from 1853 to 1860.
It was started by Marcus Spring and Rebecca Buffum (1812-1911). Maud Honeyman Green writes: "The Union established a progressive boarding school that was a pioneer in co-education. Girl students were encouraged to speak in public, engage in sports, and act in plays, activities that were frowned upon in other schools. Abolitionists Angelina Grimké and Sarah Grimké were teachers in the school which was run by Angelina’s husband, Theodore Weld. Several other noted reformers came to teach and lecture at the school. The Welds’ school operated until about 1861, but it isn’t known how long the Union itself endured."
Others who lived at Raritan Bay Union included Charles Kingsley, Caroline Kirkland and James G. Birney The early women's rights activist Clarina I. H. Nichols left her two youngest children at Raritan Bay Union when she set out with the New England Emigrant Aid Society for Kansas Territory in 1855.