middle of the nineteenth century there was something like three
millions of slaves out of a population of seven and a half millions.
Lord Palmerston estimated the total number of slaves in the sixties as
being 3,000,000;[5] whereas a writer in the "Revue des deux Mondes"
puts the number between 2,500,000 and 4,000,000.[6] Dawson quotes the
number of slaves in 1856 as being approximately 2,500,000 or forty per
cent of the total population.[7] Apparently there is no actual census
available on the number of slaves for this period. Needless to say,
the slaves easily comprised from forty to fifty per cent of the
population, and if we add all those of mixed blood we have a majority
of the inhabitants of Brazil.

Now let us turn to the Old South. Slavery we know progressed somewhat
in the southern colonies, and to a negligible extent in the New
England colonies. The "Asiento" in 1713, by which Great Britain at the
close of the War of Spanish Succession secured the right to supply the
colonies of Spain with 4,800 slaves annually,[8] augmented the slave
trade throughout the new world. Negroes were in demand in the rice
areas, cotton fields, and tobacco plantations. In 1710 there were only
50,000 slaves in the United States, the number increased to 220,000 in
1750, to 464,000 in 1770,[9] until by the year 1790 they numbered
697,624.[10] This number constituted one-fifth of our total
population.

Slavery, however, was not a venerated institution in the Southland in
the eighteenth century. In fact, it was rather supported through the
force of habit and the fear of the results of emancipation. Then came
Eli Whitney's invention of the cotton gin. The South went cotton mad.
The United States now became the world's producer of raw cotton.
Henceforth, slavery was held "the indispensable economic instrument of
southern society."[11]

In the first half of the nineteenth century, then, American slavery
was at its height. By 1850 the slaves numbered 3,204,313, about a few
thousand less than Brazil, which at the opening of the century had so
far led it in the number of slaves held.[12] Blake, writing in 1857,
shows that by the last census, however, unlike Brazil, the proportion
of black to white was not great, being in the neighborhood of fourteen
per cent. However, taking the nation in sections, the ratio of black
to white in the South was one to two, whereas in the North it was but
one to sixty-eight.[13]

As to the extent of slavery