Although many people might only blame the South for the cause for the U.S. Civil War. There were two sides to these issues and over the span of decades and for nearly a century of being a republic, the people had not taken bold enough steps to remedy and prevent was to become the Civil War.
Some people may feel that it was inevitable that the Union (the North) and the Confederacy (the South) would do battle. There is no alternate history that we can present, as this is how it occurred.
However, the attempts to delay or defer the seemingly inevitable war, which was the strategy for all of the time of the young republic, as well as the years before the formation in 1776. The time leading up to the 1861-65 battle included numerous temporary patches to compromise with both sides, when there could be no real compromise.
An excellent example of the inability to enact real compromise can be seen in the Compromise of 1850 with the Fugitive Slave Act. This act ensured that the balance in government representation of free and slave states remained the same with the expansion and addition of states like California. Obviously if one side had more power, they would quickly use it to diminish the other side's ability to confront the opposing power.
The act also tasked the free North with returning escaped slaves from the South. This North was supposed to enforce a law against its own people who opposed everything about slavery. A certain impossibility.
So while, the North may have lobbied for freedom and protected escaped or runaway slaves, the still were met in an impossible situation that could not allow compromise given their announcements of freedoms, as like that in the Constitution.
The North may have hated slavery, but they tolerated slavery and that is enough to find them as an accomplice to the act, or having been involved in some regards to allowing it to happen.
And as such, the quote and meaning of the answer, is that both the North and the South suffered and were filled with grief because they had both been active participants in allowing or encouraging slavery in the U.S. to exist.
