Much alarm was felt along our entire Atlantic seaboard lest some attack
might be made by the enemy. Every precaution was taken to prevent
possible injury to our great cities lying along the coast. Temporary
garrisons were provided, drawn from the State militia; infantry and
light batteries were drawn from the volunteer force. About 12,000 troops
were thus employed. The coast signal service was established for
observing the approach of an enemy's ships to the coast of the United
States, and the Life-Saving and Light-House services cooperated, which
enabled the Navy Department to have all portions of the Atlantic coast,
from Maine to Texas, under observation.

The auxiliary Navy was created under the authority of Congress and was
officered and manned by the Naval Militia of the several States. This
organization patrolled the coast and performed the duty of a second line
of defense.

Under the direction of the Chief of Engineers submarine mines were
placed at the most exposed points. Before the outbreak of the war
permanent mining casemates and cable galleries had been constructed at
nearly all important harbors. Most of the torpedo material was not to be
found in the market, and had to be specially manufactured. Under date
of April 19 district officers were directed to take all preliminary
measures short of the actual attaching of the loaded mines to the
cables, and on April 22 telegraphic orders were issued to place the
loaded mines in position.

The aggregate number of mines placed was 1,535, at the principal harbors
from Maine to California. Preparations were also made for the planting
of mines at certain other harbors, but owing to the early destruction of