established, from which the main American armies were to be reached and
destroyed. On the sea the navy was to be used to ruin American commerce
and to prevent the importation of supplies.

[Sidenote: American military policy.]

The policy of the Americans was, not to attempt to defend the whole coast,
but to keep as large a number of troops as they could raise together in
one body, as a substantial army; to defend their land communication from
New England to the South; and by standing ready for operations in the
field, to prevent the British from making any large detachments. They must
hold as much of their territory as possible, in order to prevent
defections; and they must take every advantage of their defensive
position, in order at length to hem in and capture the opposing armies on
the coast, as they did finally at Yorktown. The open gate through the
Hudson they strove to close early in the war by invasion of Canada. On the
sea all they could do was to capture supplies and destroy commerce, and by
the ravages of their privateers to inspire the enemy with respect.

[Sidenote: Plans frustrated.]

Neither party was able to carry out its plans. The British took all the
principal seaports, but were able to hold none, except New York, to the
end of the war. First Burgoyne and later Cornwallis made a determined
attempt to penetrate far into the interior, and both were captured. On the
other hand, the Americans could not shake off the main central army, and
there was danger to the very last that the British would beat them in one
pitched battle which would decide the war.

[Sidenote: Campaign of 1776.]