Research from the public history project Global Threads has revealed connections between the 1819 Peterloo massacre and the exploitation of enslaved Africans in the Caribbean. The study suggests that the forces exploiting cotton workers in Manchester were the same as those exploiting enslaved people thousands of miles away, a connection noted by Black abolitionist Robert Wedderburn at the time.
The research examined the life of Hugh Hornby Birley, the yeomanry commander at Peterloo, finding his family's wealth was linked to transatlantic enslavement. His family's business benefited from the estate of Daniel Backhouse, an enslaver who funded and profited from voyages trafficking over 27,000 Africans. After the emancipation of enslaved Africans in the British empire, the Birley family supported the enslaving US confederacy due to their cotton interests.
Sir George Philips, who helped fund the Manchester Guardian, was also investigated by the project. Despite his liberal politics, Philips owned the Success plantation in Hanover, Jamaica, and was invested in the exploitation of enslaved Africans. The Dreadnought, a ship that trafficked enslaved workers to Wedderburn plantations, also trafficked workers to Philips's Success plantation.
Birley and Philips were members of the Portico Library, a centre for Manchester's business elite in the 19th century. Global Threads historians stated that the leaders of Manchester's elite, Birley and Philips, owed their positions and power to family and business activities connected to colonialism and slavery.