Martin Luther King's connections to Boston are well known: He got his PhD in religion at Boston University while living on Mass. Ave. in the South End, met his wife here, later returned for a march from Roxbury to downtown.
But King's connections go further, back into Boston's history as a center of the abolition movement before the Civil War.
One of King's more quoted sayings is that "the arc of the moral universe is long, but it bends toward justice."
In his original use of the phrase, he put it inside quotation marks because he was paraphrasing Theodore Parker, a Unitarian minister from West Roxbury who got kicked out the Unitarian church (the church later reconciled with him), started his own congregation in Boston and became active in the abolition movement (in fact, was indicted for his role in trying to keep Anthony Burns, an escaped slave in Boston from being sent back South).
In 1853, Parker published a collection of sermons, including one titled Of Justice and the Conscience, in which he wrote:
Look at the facts of the world. You see a continual and progressive triumph of the right. I do not pretend to understand the moral universe, the arc is a long one, my eye reaches but little ways. I cannot calculate the curve and complete the figure by the experience of sight; I can devine it by conscience. But from what I see I am sure it bends towards justice.
Image from the Illustrated London News, Sept. 27, 1856, from the Library of Congress.