"No Chinese wall can now be tolerated...."See in text(Text of Douglass's Essay)
In this metaphor, Douglass reveals his broader vision for the United States in the wake of the Civil War. The Great Wall of China stretches along the western Chinese border and was built and maintained over millennia to keep Mongolian tribes out. Douglass views a similar, though metaphorical, wall dividing the North and South of the United States, with the South—in the mode of medieval China—resisting the North’s laws and values. Thus, along with Reconstruction, Douglass is calling for “the light of law and liberty” to flow into the South. Ultimately, Douglass is calling for national unity.
"The deadly upas, root and branch, leaf and fibre, body and sap, must be utterly destroyed...."See in text(Text of Douglass's Essay)
The upas, Antiaris toxicaria, is a tree known for the deadly poisons it produces. Douglass uses the upas as a metaphor for the systemic problems at the heart of the United States, namely slavery and inequality. Just as one must uproot and destroy the upas in its entirety, so must the United States eradicate the remaining sources of inequality.
"The yawning seam and corroded bolt conceal their defects from the mariner until the storm calls all hands to the pumps...."See in text(Text of Douglass's Essay)
Here Douglass discusses how social and political problems build up below the level of public awareness. Such a trend is particularly true in a time of prosperity and bustling busyness, as was the case in the United States—particularly the North—during the mid-19th century. The problem Douglass targets is that of class inequality, a deep disease of which Southern rebellion was a mere symptom. Only a clear crisis can alert the public to structural ills. Douglass illustrates this phenomenon with the metaphor of the broken bilge pump that goes unnoticed until a storm strikes and its disrepair becomes lamentably clear.
"The arm of the Federal government is long..."See in text(Text of Douglass's Essay)
Douglass’s use of an accessible metaphor allows him to appeal to a wider audience. Here, the “arm of the Federal government” refers to the influence it has in enforcing laws. On a connotative level, “arm” calls to mind “arms,” which also suggests that Douglass includes the military power of the Federal government in this claim. This brings up a practical perspective: enforcing the laws through Federal troops is costly, expensive, and cannot reach the rights of all individuals.
"who deliberate with daggers and vote with revolvers..."See in text(Text of Douglass's Essay)
Douglass employs the metaphors to “deliberate with daggers” and “vote with revolvers” to emphasize the danger and disloyalty of incorporating Confederate politicians into the US government. Both daggers and revolvers are weapons, so saying politicians deliberate and vote with them suggests that no constructive debate is possible. Douglass is likely referring to the former Confederates whom Congress refused to seat in December 1865.