1865: The Rainbow in the Window
Early in the Spring of 1865, as the Civil War was approaching its end, a rainbow appeared in the window of an elderly farmer named Jesse Smith at his farmhouse six miles west of Demossville, Kentucky, USA. The rainbow was first noticed on a morning after a severe storm. About six inches wide and in brilliant color, it arched across the three lower panes of his front window, and was only visible from the outside... from the inside, the window appeared fully clear. From outside, there was no denying its presence. The rainbow was somehow either in or on the glass for when the lower panes were raised, the rainbow moved up with them.
Strangely, it's said that the appearance of this rainbow caused a panic. Hundreds came to see it, all convinced that it was somehow a portent -- good or bad -- regarding the war in progress. A few days after the appearance of the rainbow, the war ended... but the rainbow itself was reported by the Cincinnati Enquirer twenty years later as still visible, distinct and brilliant in color.
This just the first note on this account, and more information will be added as I find it.