slave trading nations and continued to defy British diplomatic calls to cease trading. In 1846, Palmerston returned as foreign secretary and in 1850 permitted Royal Naval vessels to enter Brazilian waters in order to blockade slavers on both sides of the Atlantic. By 1852 the Brazilian trade could be said to be extinct. "For Palmerston … the naval campaign on the coast of Brazil had brought the long drawn-out saga of the Brazilian slave trade to a resolution within twelve months". The many years of British pressure on the United States to join vigorously in fighting the Atlantic slave trade had been neutralised by the southern states. However with the onset of the American Civil War, the Lincoln administration became eager to sign up, humanitarian and military objectives combined. To the North, anti-slavery was an important military tool with which to harm the Confederate economy. It also won praise, sympathy and support on the international stage, and dampened international support for the Southern States who vehemently defended their right to keep slaves. In the Lyons–Seward Treaty of 1862, the United States gave the UK full authority to crack down on the Atlantic slave trade when carried on by US ships. With the end of hostilities the UK and the US would continue cooperating, and in 1867, Cuba, under much pressure from the two nations, gave up its trade. United States involvement The United States Constitution of 1787 had protected the importation of slaves for twenty years. The Pennsylvania Abolition Society held its first meeting at the temporary Capital, Philadelphia, Pennsylvania, in 1794. On 7 April 1798, the fifth Congress passed an Act that imposed a $300-per-slave penalty on persons convicted of performing the illegal importation of slaves. It was an indication of the type of behaviour and course of events soon to become commonplace in the Congress. On Thursday, 12 December 1805, in the ninth Congress, Senator Stephen Roe Bradley of the State of Vermont gave notice that he should, on Monday next, move for leave to bring in a bill to prohibit the importation of certain persons therein described "into any port or place within the jurisdiction of the United States, from and after the first day of January," which will be "in the year of our Lord 1808." His words would be repeated many times by the legislators in the ninth Congress. The certain persons were described as