On January 4, 1867, President Andrew Johnson was preparing his veto of the District [of Columbia] Suffrage Bill, telling his cabinet of issues with the Bill. He pointed out that “New York Negroes were obliged to comply with property requirements not necessary for white voters”, while other Northern States like Pennsylvania and Indiana excluded them from voting altogether.”
Johnson added that “the representatives of States where suffrage is either denied the colored man or grant [voting rights on qualifications being met] . . . should compel the people of the District of Columbia to try an experiment which their own constituents have thus far shown an unwillingness to test for themselves . . .” It was clear to Johnson that the motivation for Negro suffrage was the voting potential they held, and the potential for Republican Party political hegemony in the future. This led to virtually unbroken Republican national rule until Woodrow Wilson.
It is noteworthy that when the Emancipation Bill of April 1862 provided freedom for colored people in the District, which also compensated their owners, Lincoln insisted that the measure be coupled with a $100,000 appropriation to settle the freedmen in Haiti and Liberia.
Radical Experiment in the District
“The question of voting by Negroes had become by this time a burning national issue and one on which the Republican Party was by no means unanimous. Even in the North only six States permitted Negro suffrage without restrictions. Negroes were not permitted to vote in Pennsylvania, Ohio, Indiana and Illinois, and . . . New York still maintained property qualifications for Negro voters.
The Radical wing of the Party, led by [Charles] Sumner and Thaddeus Stevens, was, however, adamant on this issue. It was essential in their opinion that the colored man should be permitted to vote . . . [and] the control of the Southern States by the Republican Party could be maintained by the Negro vote, since it was quite inconceivable that the vast majority of Negroes would vote for any other Party than the Republicans who had freed them.
Realizing the difficulties of achieving Negro suffrage in the States, the leaders of the Radical Wing of the Republican Party began to turn their attention to the District of Columbia over which Congress had jurisdiction.
If Negro suffrage could be achieved in the District, with its large colored population, that would set the standard which some of the Southern States might be eventually be persuaded or compelled to follow.
Thus the municipal politics of Washington and Georgetown were to become a vital issue in the struggle for power between the Radical Republicans in Congress and Andrew Johnson, the Conservative Democrat in the White House.”
(The Uncivil War: Washington During the Reconstruction, 1865-1878, James H. Whyte, Twayne Publishers, 1958, excerpts pg. 37)