The pus collection causes pressure on the spinal cord. The infection is usually due to bacteria. Often it is caused by a staphylococcus infection that spreads through the spine. It may be caused by tuberculosis in some areas of the world, but it is not as common today as it was in the past.
From the 1830s until 1870, the abolitionist movement attempted to achieve immediate emancipation of all slaves and the ending of racial segregation and discrimination.
During ensuing decades, the abolitionist movement grew in Northern states, and Congress regulated the expansion of slavery as new states were admitted to the Union. Britain banned the importation of African slaves in its colonies in 1807 and abolished slavery in the British Empire in 1833.