<P> Bartolomé de las Casas was a 16th - century Spanish Dominican priest, the first resident Bishop of Chiapas . As a settler in the New World he witnessed and opposed the poor treatment of the Native Americans by the Spanish colonists . He advocated before King Charles V, Holy Roman Emperor on behalf of rights for the natives . Originally supporting the importation of African slaves as labourers, he eventually changed and became an advocate for the Africans in the colonies . His book, A Short Account of the Destruction of the Indies, contributed to Spanish passage of colonial legislation known as the New Laws of 1542, which abolished native slavery for the first time in European colonial history . It ultimately led to the Valladolid debate . </P> <P> During the early 19th century, slavery expanded rapidly in Brazil, Cuba, and the United States, while at the same time the new republics of mainland Spanish America became committed to the gradual abolition of slavery . During the Independence Wars (1810--1826), slavery was abolished in most of Latin America . Slavery continued until 1873 in Puerto Rico, 1886 in Cuba, and 1888 in Brazil by the Lei Áurea or "Golden Law ." Chile declared freedom of wombs in 1811, followed by the United Provinces of the River Plate in 1813, but without abolishing slavery completely . While Chile abolished slavery in 1823, Argentina did so with the signing of the Argentine Constitution of 1853 . Colombia abolished slavery in 1852 . Slavery was abolished in Uruguay during the Guerra Grande, by both the government of Fructuoso Rivera and the government in exile of Manuel Oribe . </P> <P> While many blacks who arrived in Nova Scotia during the American Revolution were free, others were not . Black slaves also arrived in Nova Scotia as the property of White American Loyalists . In 1772, prior to the American Revolution, Britain outlawed the slave trade in the British Isles followed by the Knight v. Wedderburn decision in Scotland in 1778 . This decision, in turn, influenced the colony of Nova Scotia . In 1788, abolitionist James Drummond MacGregor from Pictou published the first anti-slavery literature in Canada and began purchasing slaves' freedom and chastising his colleagues in the Presbyterian church who owned slaves . In 1790 John Burbidge freed his slaves . Led by Richard John Uniacke, in 1787, 1789 and again on 11 January 1808, the Nova Scotian legislature refused to legalize slavery . Two chief justices, Thomas Andrew Lumisden Strange (1790--1796) and Sampson Salter Blowers (1797--1832) were instrumental in freeing slaves from their owners in Nova Scotia . They were held in high regard in the colony . By the end of the War of 1812 and the arrival of the Black Refugees, there were few slaves left in Nova Scotia . (The Slave Trade Act outlawed the slave trade in the British Empire in 1807 and the Slavery Abolition Act of 1833 outlawed slavery all together .) </P> <P> With slaves escaping to New York and New England, legislation for gradual emancipation was passed in Upper Canada (1793) and Lower Canada (1803). In Upper Canada the Assembly ruled that no slaves could be imported; slaves already in the province would remain enslaved until death, no new slaves could be brought into Upper Canada, and children born to female slaves would be slaves but must be freed at the age of 25 . In practice, some slavery continued until abolished in the entire British Empire in the 1830s . </P>

When did the abolitionist movement begin and end