[1] After abolishing the slave trade in its empire in 1807 and winning a decisive victory in the Napoleonic Wars in 1815, Britain created "Mixed Commission Courts" with several other European nations and the United States in the early to mid-nineteenth century.
Although the United States had abolished its own international slave trade in 1808, it initially declined overtures to participate in mixed courts as part of its treaty arrangements with Britain.
[2] During the American Civil War, however, the Lincoln administration was eager to avoid the prospect of Britain supporting the Confederate States of America in the interests of reopening the transatlantic cotton trade.
It conceded to Britain the right of search to a limited extent in African and Cuban waters, but secured a similar concession for American war vessels from the British government.
The treaty created three mixed courts to be staffed by an equal number of British and American judges for the purposes of adjudicating cases arising under its provisions.
In cases in which the British and American judge disagreed on a significant issue, the regulations annexed to the treaty set up an unusual tiebreaking system, whereby both nations appointed an 'adjudicator', one of whom was selected by the drawing of lots.