We reflect on the Emancipation Proclamation, issued by President Abraham Lincoln 150 years ago to mend a Nation half-slave and half-free under the unifying promise of liberty.

WHITEHOUSE: Presidential Proclamation -- Law Day, 2013

We trace generations of African Americans, free and slave, who risked everything to realize their God-given rights.

WHITEHOUSE: The White House

Many U.S. institutions were deliberately designed to tolerate the coexistence of free states and slave-owning states.

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Some of Congress's fiercest fights were over the admission of new states to the union, and whether they should be slave or free.

ECONOMIST: American democracy

In giving freedom to the slave, we assure freedom to the free honorable alike in what we give, and what we preserve.

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The nine-hour Belfast tour (an epic in itself) takes in sites around Northern Ireland, including the caves where red priestess Melisandre of Asshai gave birth to an evil shadow-baby assassin, and Ballycastle, setting for the Free Cities where the eunuch Lord Varys was born as a slave.

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In the 18th century, it was home to one of the largest population of free blacks in the New World even as it became one of the centers of the global slave trade and home to some of its most violent abuses.

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