use to have negotiations reopened with England, but
without success.[45] Indeed, the chances of success were now for many
years imperilled by the recurrence of deliberate search of American
vessels by the British.[46] In the majority of cases the vessels proved
to be slavers, and some of them fraudulently flew the American flag;
nevertheless, their molestation by British cruisers created much
feeling, and hindered all steps toward an understanding: the United
States was loath to have her criminal negligence in enforcing her own
laws thus exposed by foreigners. Other international questions connected
with the trade also strained the relations of the two countries: three
different vessels engaged in the domestic slave-trade, driven by stress
of weather, or, in the "Creole" case, captured by Negroes on board,
landed slaves in British possessions; England freed them, and refused to
pay for such as were landed after emancipation had been proclaimed in
the West Indies.[47] The case of the slaver "L'Amistad" also raised
difficulties with Spain. This Spanish vessel, after the Negroes on board
had mutinied and killed their owners, was seized by a United States
vessel and brought into port for adjudication. The court, however, freed
the Negroes, on the ground that under Spanish law they were not legally
slaves; and although the Senate repeatedly tried to indemnify the
owners, the project did not succeed.[48]

Such proceedings well illustrate the new tendency of the pro-slavery
party to neglect the enforcement of the slave-trade laws, in a frantic
defence of the remotest ramparts of slave property. Consequently, when,
after the treaty of 1831, France and England joined in urging the
accession of the United States to it, the British minister was at last
compelled to inform Palmerston, December, 1833, that "the Executive at
Washington appears to shrink from bringing forward, in any shape, a
question, upon which depends the completion of their former object--the
utter and universal Abolition of the Slave Trade--from an apprehension
of alarming the Southern States."[49] Great Britain now offered to sign
the proposed treaty of 1824 as amended; but even this Forsyth refused,
and stated that the United States had determined not to become "a party
of any Convention on the subject of the Slave Trade."[50]

Estimates as to the extent of the slave-trade agree that the traffic to
North and South America in 1820 was considerable, certainly not