e another illustration of
this point. More than one-third of the exports of Great Britain were
made to North America, the West Indies, and Africa. They stood thus
during the three years ending at Christmas, 1773:

Annual average exports to North America $17,500,000
To the West Indies 6,500,000
To Africa 3,500,000
----------
Total value of exports $27,500,000

But this is not all. The total value of the exports of Great Britain to
all the world, at this date, was $80,000,000. These exports were made
up, in part, of colonial products, tobacco, rice, sugar, etc., to the
amount of $15,000,000;--$5,000,000 to foreign countries, and $10,000,000
to Ireland,--which, when added to the $27,500,000, paid for by the
colonies, exhibits them as sustaining more than one-half of the commerce
of the mother country.[108]

The immediate cause of the alarm which led to the examination of this
subject by the Hon. Edmund Burke, and others, of the British Parliament,
was the adoption, by the North American colonies, of the policy of
non-importation and non-consumption of all English products, whether
from the mother country, or any of her colonies; and the non-exportation
of any North American products to Great Britain, the West Indies, or any
of the dependencies of the crown. This agreement was adopted as a
measure of retaliation upon Parliament, for the passage of the Boston
Port Bill, which ordered the closing of Boston harbor to all commerce.
The measure was first proposed at a meeting of the citizens of Boston,
held on May 13, 1774. It was soon seconded by all the principal cities,
towns, and counties, throughout the colonies; and when the Continental
Congress met at Philadelphia, the terms of the league were drawn up and
adopted, October 20, 1774, and went into operation.

A few extracts from memorials to Parliament, praying that the
difficulties with North America might be adjusted, and the threatened
evils averted, will show how the slave trade was then interwoven with
the commerce and national prosperity of Great Britain, and to what
extent the American league could affect that prosperity.

In the House of Commons, January 23, 1775: "Mr. Burke then presented a
petition of the Master, Wardens, and Commonalty, of the Society of
Merchants Venturer