Final answer:
The quote 'At last, through long, our jarring notes agree/and time it is when raging war is done/to smile at 'scapes and perils overblown' is from the poem 'Rome' by Henry Timrod, and it reflects on the aftermath of war and the moment when peace is finally achieved.
Step-by-step explanation:
The quote 'At last, through long, our jarring notes agree/and time it is when raging war is done/to smile at 'scapes and perils overblown' is from the poem 'Rome' by Henry Timrod. This poem was written during the American Civil War, and it reflects on the aftermath of war and the moment when peace is finally achieved. The quote emphasizes the relief and joy that comes with the end of conflict and the ability to look back on the dangers and struggles that have been overcome. It suggests a sense of unity and harmony after a period of discord and violence.