, must inevitably split into two,
perhaps three, rival empires, a slave-holding one in the South, free
nations in North and West.

The fate of Texas sealed, Britain soon definitely abandoned all
opposition to American expansion unless it were to be attempted
northwards, though prophesying evil for the American madness. Mexico,
relying on past favours, and because of a sharp controversy between the
United States and Great Britain over the Oregon territory, expected
British aid in her war of 1846 against America. But she was sharply
warned that such aid would not be given, and the Oregon dispute was
settled in the Anglo-Saxon fashion of vigorous legal argument, followed
by a fair compromise. The Mexican war resulted in the acquisition of
California by the United States. British agents in this province of
Mexico, and British admirals on the Pacific were cautioned to take no
active steps in opposition.

Thus British policy, after Texan annexation, offered no barrier to
American expansion, and much to British relief the fear of the extension
of the American plans to Mexico and Central America was not realized.
The United States was soon plunged, as British statesmen had prophesied,
into internal conflict over the question whether the newly-acquired
territories should be slave or free.

The acquisition of California brought up a new problem of quick transit
between Atlantic and Pacific, and a canal was planned across Central
America. Here Britain and America acted together, at first in amity,
though the convention signed in 1850 later developed discord as to the
British claim of a protectorate over the Atlantic end of the proposed
canal at San Juan del Nicaragua. But Britain was again at war in Europe
in the middle 'fifties, and America was deep in quarrel over slavery at
home. On both sides in spite of much diplomatic intrigue and of
manifestations of national pride there was governmental desire to avoid
difficulties. At the end of the ten-year period Britain ceded to
Nicaragua her protectorate in the canal zone, and all causes of
friction, so reported President Buchanan to Congress in 1860, were
happily removed. Britain definitely altered her policy of opposition to
the growth of American power.

In 1860, then, the causes of governmental antagonisms were seemingly all
at an end. Impressment was not used after 1814. The differing theories
of the two Governments on British expatriation still remained, but
Britain attempt