“Group of people bowling on a wooden lane erected in a yard,” July 4, 1861, via Library of Congress Prints and Photographs Division.
I just found this photo. It was taken exactly one year before yesterday’s picture, probably by James Hunter,* who would host the 1862 picnic.
The Library’s online catalogue says that “Mrs. H. Bowling and Coleman Sellers, Jr.,” have been identified in this image, although it doesn’t say where they are — probably the woman bowling (Mrs. H., bowling†) and perhaps the boy in charge of setting up the pins.

“By the mid-1800s, the game of ninepins was so popular that wealthy families installed bowling lanes at their estates. . . , ” according to American Profile. “When some states outlawed ninepins [in the 1830s and 40s] because it encouraged gambling, the modern game of tenpins evolved to skirt the laws.” I’m not sure if there are nine pins in this picture or ten. What looks like one middle pin may be two pins lined up.
The image is part of the Charles F. Himes collection of stereographs by amateur photographers, primarily members of the Pennsylvania Photographic Society (1860-61) and the Amateur Photographic Exchange Club (1861-63).
*James Hunter may have been co-owner of the Print and Dye Works in Hestonville, Pennsylvania.
†H. for Hunter? Coleman Junior’s father was Coleman Sellers II, a prominent engineer and inventor from Philadelphia. — as well as an amateur photographer.