"Black Republican" (term)
The founding of the term "Black Republican" is often attributed to incumbent Stephen Douglas, a Democrat scheduled to have seven debates with Republican Kentucky native Abraham Lincoln; both were campaigning for an Illinois Senate seat in 1858.
The primary theme of the debates was slavery, and Douglas accused Lincoln and members of the the "Black Republican Party" of being abolitionists against slavery in the Western territories. Lincoln lost the bid for the Illinois Senate seat but won the nomination to run for U.S. President during the 1860 Republican National Convention in Chicago. During the presidential campaign, Abraham Lincoln was often referred to as the "Black Republican." The term was also used during the Reconstruction Era for Republicans who supported legislation that favored African Americans.
For more see the "Black Republican" entry in vol. 2 of the Afro-American Encyclopedia; and Lincoln and Douglas, by A. C. Guelzo.