On the evening of July 20, 1860, he happened to be looking south at 9:49 pm in evening, and saw a spectacular train of fireballs streaking through the summer sky.
The Meteor of 1860 - Frederic Church
Being an artist, he painted what he saw that night from memory.
The same year, Walt Whitman, living in New York City, wrote a poem entitled Year of Meteors (1859-60) which was published in his well-known Leaves of Grass collection. Part of it reads:
...the strange huge meteor procession, dazzling and
clear, shooting over our heads,
|(A moment, a moment long, it sail'd its balls of unearth-|
ly light over our heads,
|Then departed, dropt in the night, and was gone;)|
Even though this meteor caused a stir throughout the Northeast, and was the subject of hundreds of newspaper articles over the next few days, memory of it eventually faded.
Harper's Weekly coverage of the meteor
Path of the July 20, 1860 meteor
By the mid-twentieth century, scholars of Whitman were ascribing the description in his poem to a number of different meteor showers and events in the mid-1800s. In 2010, however, a group of two physics professors, an English professor, and a student from Texas State University connected the dots and figured out that the 1860 meteor, Church's painting, and Whitman's poem were all describing the same event - no one had made that connection before. They published in the July 2010 issue of Sky & Telescope (the 150th anniversary of the meteor).
The July, 1860 meteor was actually an interesting and spectacular event. It represents an Earth grazing meteor procession. Earth grazing meteors are those which pass through the atmosphere without colliding with the surface. They move horizontally and appear in the sky for a long time (for meteorites, that is - they can be seen by observers for up to a minute compared to the flash in the pan for most meteorite sightings). A procession occurs when the meteorite breaks up into fragments from the stresses of passing through the Earth's atmosphere. They're fairly rare events - the last one was on February 9 of 1913.
It's always good for scientists to read poems and look at paintings once in a while!