All slavery has its origin in power and is against right.
To the constitutional theory advanced by the Chief-Justice, that Congress cannot exercise sovereign powers over Federal Territories, and hence cannot exclude slave property from them, Justices McLean and Curtis also opposed a vigorous and exhaustive argument, which the most eminent lawyers and statesmen of that day deemed conclusive.

The historical precedents alone ought to have determined the issue.

"The judicial mind of this country, State and Federal," said McLean, "has agreed on no subject within its legitimate action with equal unanimity as on the power of Congress to establish Territorial governments.

No court, State or Federal, no judge or statesman, is known to have had any doubts on this question for nearly sixty years after the power was exercised." [Sidenote] 19 Howard, p.

619.
And Curtis added: "Here are eight distinct instances, beginning with the first Congress, and coming down to the year 1848, in which Congress has excluded slavery from the territory of the United States; and six distinct instances in which Congress organized governments of Territories by which slavery was recognized and continued, beginning also with the first Congress, and coming down to the year 1822.