The following years witnessed an increased campaign for the restriction and abolition of slavery, and the District of Columbia became the focal point of the conflicting arguments. At first the Congress did not deny its own right to legislate in all areas affecting the District. However, as northern abolitionists began to pit themselves directly against the southern gentry, the question of constitutional authority became of increased importance. The South viewed abolition of slavery and the slave trade in the District as the first step towards the general abolition of the domestic institution.
Constitutional issues, such as the right of petition, the right of property, and the scope of Congressional power, as well as moral issues, were argued on both sides. During this period the campaign began to focus on the cessation of the slave trade in the District as a compromise measure. Abraham Lincoln, who was later to gain much credit for the total abolition of slavery in the United States, for one, however, was not always in sympathy with measures proposed to eliminate slavery. He voted against Congressman Daniel Gott's resolution of December 21, 1848 that "whereas the traffic now prosecuted in this metropolis of the Republic in human beings, as chattels, is contrary to natural justice and the fundamental principles of our political system, and is notoriously a reproach to our country throughout Christendom, and a serious hindrance to the progress of republican liberty among the nations of the earth: Therefore, resolved that the Committee for the District of Columbia be instructed to report a bill, as soon as practicable, prohibiting the slave trade in said District."2 Although this proposal met with little success, the Compromise of 1850 did bring an end to the slave trade in the District of Columbia. Earlier, the Treaty of Washington, August 9, 1842, officially ended U. S. and British participation in the African Trade.
Eventually, the institution of slavery was abolished in the District of Columbia on April 16, 1862. Lincoln's emancipation of slaves in the seceded states did not become effective until January 1, 1863, and it took the thirteenth amendment to the Constitution, December 18, 1865, to completely abolish slavery in those states which remained loyal to the Union. Throughout this period, the District of Columbia remained the central point in the slavery issue. Perhaps it was only fitting that an issue key to the survival of the United States as a single, sovereign nation would be fought on the neutral ground of the capital city.