Curbstone Press was founded in 1975 in Connecticut and aims to use literature to widen the horizons of individuals and bring much needed attention and understanding to various cultural, social, and human rights issues around the world. Basically they encourage a better understanding of our world through reading.
Curbstone not only publishes literary works that further its mission (usually 8-10 books a year) but it also promotes literacy and the appreciation of literature through various programs (i.e. they bring writers into high schools to speak with students). You can support them through donating or by looking for their books in a store or library near you.