ce of the river mouths with a view to resisting any
offensive movement. The federalist party on the other hand were in
favour of energetic action against France, so as to secure English
favour and the great commercial privileges which the mistress of the
seas could bestow. For a time no hostilities resulted, but constant
irritation was caused by the British claim to a right of search and to
the impressment of sailors of British nationality found on American
ships, while American ships accused of infringing the blockade were
seized by either of the European combatants. To some extent the
differences between Great Britain and the United States depended on
rival views of the law of allegiance. The British maintained the
doctrine _nemo potest exuere patriam_, and regarded all British-born
persons, unless absolved from their allegiance by the act of the
mother-country, as British subjects. The law of the United States, on
the other hand, permitted an alien to become a citizen after fourteen
years' residence, and previously to 1798 had required a residence of
five years only. In this way it often happened that sailors who had
received the American citizenship were impressed for service on British
ships, and sometimes sailors of actual American birth were impressed.
But it was impossible to justify the practice to which the Americans
resorted of receiving deserters of British nationality from British
ships of war, who were induced by offers of higher pay to transfer
themselves to the American service.

Jefferson at first preferred to coerce the European powers by
retaliatory legislation. As early as April, 1806, a law had been passed
forbidding the importation of certain British wares, but was suspended
six weeks after it came into operation. In June, 1807, irritation was
intensified by the incident of the _Leopard_ and the _Chesapeake_. Five
men, four of whom were British born and one an American by birth, were
known to have deserted from the British sloop _Halifax_, lying in
Hampton roads, and to have taken service on an American frigate, the
_Chesapeake_. After application for their surrender had been made in
vain to the magistrates of the town of Norfolk, where the _Chesapeake's_
rendezvous was, and to the officer commanding the rendezvous,
Vice-admiral Berkeley sent his flagship, the _Leopard_, carrying fifty
guns, with an order to the British captains on the North American
station to search the _Chesapeake_ for deserters