Answer:
he delivered an eulogy at New York's Cooper Union.
Step-by-step explanation:
Throughout his career, Frederick Douglass has openly admitted for Abraham Lincoln. He praised him as the first US president who actually see black people as human beings and thanked his large contribution in the ending of slavery.
After Lincoln was assassinator, the government held a memorial. But, they did not allow Black citizens to enter the memorial.
So, Frederick Douglass held a separate memorial at New York's cooper Union where black community leaders were invited to bid farewell and said their piece to the fallen president.