Question: Who abolished slavery throughout the empire that practiced indirect rule with their African colonies?

full_context: Document 1: Imperialism: A resurgence came in the late 19th century, with the Scramble for Africa and major additions in Asia and the Middle East. The British spirit of imperialism was expressed by Joseph Chamberlain and Lord Rosebury, and implemented in Africa by Cecil Rhodes. The pseudo-sciences of Social Darwinism and theories of race formed an ideological underpinning during this time. Other influential spokesmen included Lord Cromer, Lord Curzon, General Kitchner, Lord Milner, and the writer Rudyard Kipling. The British Empire was the largest Empire that the world has ever seen both in terms of landmass and population. Its power, both military and economic, remained unmatched.
Document 2: Protestantism: Also, other human rights were advocated for by some Protestants. For example, torture was abolished in Prussia in 1740, slavery in Britain in 1834 and in the United States in 1865 (William Wilberforce, Harriet Beecher Stowe, Abraham Lincoln - against Southern Protestants). Hugo Grotius and Samuel Pufendorf were among the first thinkers who made significant contributions to international law. The Geneva Convention, an important part of humanitarian international law, was largely the work of Henry Dunant, a reformed pietist. He also founded the Red Cross.
Document 3: Imperialism: During the 20th century, historians John Gallagher (1919–1980) and Ronald Robinson (1920–1999) constructed a framework for understanding European imperialism. They claim that European imperialism was influential, and Europeans rejected the notion that "imperialism" required formal, legal control by one government over another country. "In their view, historians have been mesmerized by formal empire and maps of the world with regions colored red. The bulk of British emigration, trade, and capital went to areas outside the formal British Empire. Key to their thinking is the idea of empire 'informally if possible and formally if necessary.'"[attribution needed] Because of the resources made available by imperialism, the world's economy grew significantly and became much more interconnected in the decades before World War I, making the many imperial powers rich and prosperous.
Document 4: New York City: Under New York State's gradual abolition act of 1799, children of slave mothers were born to be eventually liberated but were held in indentured servitude until their mid-to-late twenties. Together with slaves freed by their masters after the Revolutionary War and escaped slaves, a significant free-black population gradually developed in Manhattan. Under such influential United States founders as Alexander Hamilton and John Jay, the New York Manumission Society worked for abolition and established the African Free School to educate black children. It was not until 1827 that slavery was completely abolished in the state, and free blacks struggled afterward with discrimination. New York interracial abolitionist activism continued; among its leaders were graduates of the African Free School. The city's black population reached more than 16,000 in 1840.
Document 5: Modern history: The major European powers laid claim to the areas of Africa where they could exhibit a sphere of influence over the area. These claims did not have to have any substantial land holdings or treaties to be legitimate. The European power that demonstrated its control over a territory accepted the mandate to rule that region as a national colony. The European nation that held the claim developed and benefited from their colony’s commercial interests without having to fear rival European competition. With the colonial claim came the underlying assumption that the European power that exerted control would use its mandate to offer protection and provide welfare for its colonial peoples, however, this principle remained more theory than practice. There were many documented instances of material and moral conditions deteriorating for native Africans in the late nineteenth and early twentieth centuries under European colonial rule, to the point where the colonial experience for them has been described as "hell on earth."
Document 6: Buganda Agreement (1900): The agreement was signed by Buganda's Katikiro Sir Apolo Kagwa, on the behalf of the Kabaka (Daudi Chwa) who was at that time an infant, and Sir Harry Johnston on the behalf of the British colonial government. The agreement solidified the power of the largely Protestant 'Bakungu' client - chiefs, led by Kagwa. London sent only a few officials to administer the country, relying primarily on the Bakungu chiefs. For decades they were preferred because of their political skills, their Christianity, their friendly relations with the British, There are their ability to collect taxes, and the proximity of Entebbe (the Uganda capital) was close to the Buganda capital. By the 1920s the British administrators were more confident, and have less need for military or administrative support.
Document 7: British Empire: With support from the British abolitionist movement, Parliament enacted the Slave Trade Act in 1807, which abolished the slave trade in the empire. In 1808, Sierra Leone was designated an official British colony for freed slaves. The Slavery Abolition Act passed in 1833 abolished slavery in the British Empire on 1 August 1834 (with the exception of St. Helena, Ceylon and the territories administered by the East India Company, though these exclusions were later repealed). Under the Act, slaves were granted full emancipation after a period of 4 to 6 years of "apprenticeship".
Document 8: Baptists: Elsewhere in the Americas, in the Caribbean in particular, Baptist missionaries took an active role in the anti-slavery movement. In Jamaica, for example, William Knibb, a prominent British Baptist missionary, worked toward the emancipation of slaves in the British West Indies (which took place in 1838). Knibb also protagonised the creation of "Free Villages"; rural communities centred around a Baptist church where emancipated slaves could farm their own land. Baptists were likewise active in promoting the education of former slaves; for example, Jamaica's Calabar High School, named after the slave port of Calabar, was formed by Baptist missionaries. At the same time, during and after slavery, slaves and free formed their own Spiritual Baptist movements - breakaway spiritual movements which often expressed resistance to oppression.
Document 9: Saint Helena: Although the importation of slaves to St Helena had been banned in 1792, the phased emancipation of over 800 resident slaves did not take place until 1827, which was still some six years before the British Parliament passed legislation to ban slavery in the colonies.
Document 10: Slavery in international law: The concept has its roots in the 1807 Abolition of Slavery Act of Great Britain. Many academics in the field perceive this as the beginning of the end of the traditional form of slavery: chattel slavery. In the 19th century, Britain controlled the majority of the world through its colonies. Consequently, in passing this law to abolish slavery, the British Parliament abolished slavery in the vast majority of its colonies.
Document 11: Slave Trade Act 1807: The Slave Trade Act 1807, officially An Act for the Abolition of the Slave Trade, was an Act of the Parliament of the United Kingdom prohibiting the slave trade in the British Empire. Although it did not abolish the practice of slavery, it did encourage British action to press other nations states to abolish their own slave trades.
Document 12: Imperialism: Some have described the internal strife between various people groups as a form of imperialism or colonialism. This internal form is distinct from informal U.S. imperialism in the form of political and financial hegemony. This internal form of imperialism is also distinct from the United States' formation of "colonies" abroad. Through the treatment of its indigenous peoples during westward expansion, the United States took on the form of an imperial power prior to any attempts at external imperialism. This internal form of empire has been referred to as "internal colonialism". Participation in the African slave trade and the subsequent treatment of its 12 to 15 million Africans is viewed by some to be a more modern extension of America's "internal colonialism". However, this internal colonialism faced resistance, as external colonialism did, but the anti-colonial presence was far less prominent due to the nearly complete dominance that the United States was able to assert over both indigenous peoples and African-Americans. In his lecture on April 16, 2003, Edward Said made a bold statement on modern imperialism in the United States, whom he described as using aggressive means of attack towards the contemporary Orient, "due to their backward living, lack of democracy and the violation of women’s rights. The western world forgets during this process of converting the other that enlightenment and democracy are concepts that not all will agree upon".
Document 13: British Raj: The British Raj (/ rɑːdʒ /; from rāj, literally, ``rule ''in Hindustani) was the rule by the British Crown in the Indian subcontinent between 1858 and 1947. The rule is also called Crown rule in India, or direct rule in India. The region under British control was commonly called India in contemporaneous usage, and included areas directly administered by the United Kingdom, which were collectively called British India, and those ruled by indigenous rulers, but under British tutelage or paramountcy, and called the princely states. The de facto political amalgamation was also called the Indian Empire and after 1876 issued passports under that name. As India, it was a founding member of the League of Nations, a participating nation in the Summer Olympics in 1900, 1920, 1928, 1932, and 1936, and a founding member of the United Nations in San Francisco in 1945.
Document 14: Indirect rule: The ideological underpinnings, as well as the practical application, of indirect rule in Kenya and Nigeria is usually traced to the work of Frederick Lugard, the High Commissioner of the Protectorate of Northern Nigeria from 1899 to 1906. In the lands of the Sokoto Caliphate, conquered by the British Empire at the turn of the century, Lugard instituted a system whereby external, military, and tax control was operated by the British, while most every other aspect of life was left to local pre-British aristocracies who may have sided with the British during or after their conquest. The theory behind this solution to a very practical problem (a problem referred to as' The Native Problem 'by Mahmood Mamdani in his work Citizen and Subject) of domination by a tiny group of foreigners of huge populations is laid out in Lugard's influential work, The Dual Mandate in British Tropical Africa.
Document 15: British Empire: Two years later, the Royal African Company was inaugurated, receiving from King Charles a monopoly of the trade to supply slaves to the British colonies of the Caribbean. From the outset, slavery was the basis of the British Empire in the West Indies. Until the abolition of the slave trade in 1807, Britain was responsible for the transportation of 3.5 million African slaves to the Americas, a third of all slaves transported across the Atlantic. To facilitate this trade, forts were established on the coast of West Africa, such as James Island, Accra and Bunce Island. In the British Caribbean, the percentage of the population of African descent rose from 25 percent in 1650 to around 80 percent in 1780, and in the 13 Colonies from 10 percent to 40 percent over the same period (the majority in the southern colonies). For the slave traders, the trade was extremely profitable, and became a major economic mainstay for such western British cities as Bristol and Liverpool, which formed the third corner of the so-called triangular trade with Africa and the Americas. For the transported, harsh and unhygienic conditions on the slaving ships and poor diets meant that the average mortality rate during the Middle Passage was one in seven.
ground_truth: The Slavery Abolition Act
sub_queries: who practiced indirect rule with their african colonies Answer: the British Empire
What abolished slavery throughout the British Empire ? Answer: The Slavery Abolition Act