Luke identified this passage in Kaiser Aetna v. United States, 444 U.S. 164, 177 (1979):
Distinctions between cases . . . may seem fine, indeed, in the light of hindsight, but perhaps for the very reason that it is hindsight which we now exercise, the shifting back and forth of the Court in this area until the most recent decisions bears the sound of "Old, unhappy, far-off things, and battles long ago."
The quote comes from William Wordsworth's poem, The Solitary Reaper:
Will no one tell me what she sings? --
Perhaps the plaintive numbers flow
For old, unhappy, far-off things,
And battles long ago:
Or is it some more humble lay,
Familiar matter of to-day?
Some natural sorrow, loss, or pain,
That has been, and may be again?
An annotation by the University of Toronto Library explains the origin of this poem:
Coleridge, Wordsworth, and his sister had visited the Scottish Highlands in 1803. Dorothy's Recollections for September 13 that year notes: "It was harvest time, and the fields were quietly -- might I be allowed to say pensively? -- enlivened by small companies of reapers. It is not uncommon in the more lonely parts of the Highlands to see a single person so employed." In a note to the 1807 edition, Wordsworth traced the poem's source: "This Poem was suggested by a beautiful sentence in a MS Tour in Scotland written by a Friend, the last line being taken from it verbatim." Thomas Wilkinson's manuscript, Tours to the British Mountains (London, 1824), states: "Passed a Female who was reaping alone: she sung in Erse as she bended over her sickle; the sweetest human voice I ever heard: her strains were tenderly melancholy, and felt delicious, long after they were heard no more" (12).
Congratulations to Luke. I will try to run contests of this sort on an irregular basis.