The origin of the word "picnic" is unclear. It first appeared in an English dictionary in 1748, and it probably derived from the French pique-nique.
A 17th-century French pique-nique may have been what we now think of as a potluck. In the 18th century, its American counterpart may have been more like a salon gathering. By the 19th century, though, it had become common for Americans to hold these events outside.
Although a picnic is usually a social event, the explorer Joseph Rock in 1910 captured this solitary setting among the pine forests in the foothills of Lijiang, China. (Related: "National Geographic Photography Milestones")