Boston, Massachusetts: Ticknor and Fields December 1866. First Edition. [2-ads], -772, iv, [4-ads], 8 pages. 6 1/2 x 10 inches. Buff wrappers printed in black ink. The entire issue offered (The Atlantic Monthly, December 1866, Vol 18, Number 110). Uncut, untrimmed. Minor creasing, soft crease down the front panel, a touch of soiling, an excellent example. The article is found on pages 761-765. While unsigned in the text, Frederick Douglass is identified as the author in the indices on page iii. Near Fine. Wraps. 
The Atlantic Monthly, in Gillian B. White's June 16, 2020 article: "163 years of The Atlantic’s writing on race and racism in America: How Did We Get Here?" lists dozens of papers (including this one) highlighting the most important works they've published on race and racism in America. This is one of only seven articles under the heading "Calls for Abolition, Civil War, Emancipation"
"One of the invaluable compensations of the late Rebellion is the highly instructive disclosure it made of the true source of danger to republican government. Whatever may be tolerated in monarchical and despotic governments, no republic is safe that tolerates a privileged class, or denies to any of its citizens equal rights and equal means to maintain them. What was theory before the war has been made fact by the war." p 762.
There is little this writer can say about Douglass that hasn't already been said. He was an important voice for many many years - for those unfamiliar with him, Wikipedia will provide an introduction and pointers for further research.
Here offered in the original wrappers. Most often found in bound volumes, nice copies in wrappers (as here) are increasingly scarce.