The Great Trek of the 1830s was the migration of white settlers in the area known as Boers. The Great Trek begin in 1836 and ran into the 1840s, explains How Stuff Works.
The Boers were white settlers of mostly Dutch decent. When the British imposed rule over the area in 1815, the Boers opposed the rule and migrated into South Africa. When the English settlers began to arrive in 1820 and slavery was abolished by the British in 1834, opposition to their rule grew stronger. During the course of the Great Trek, over 18,000 Boers migrated, leaving the Cape Colony behind. These individuals where nicknamed "voortrekkers." The independent republic of Natalia was established by the Boers in 1839, followed by Transvaal in 1852 and Orange Free State in 1854. This independence established a new way of life for the Boers and brought them a new future in the area. Their numbers began to grow and they soon had a large community based in the South African areas. The creation of a commission and the articles to be followed by each of the republics were established with rules relating to who could come and go on the property and what residents were entitled to under the law.