Fisher’s What Mrs. Fisher Knows About Old Southern Cooking, Soups, Pickles, Etc.  (1881) Is the second oldest African-American cookbook.  When she does relate food to a particular meal, it’s Breakfast cream cake or Waffles for breakfast.  She does not mention a picnic of any kind in her text. Fried chicken, however, is a picnic staple. 

Fried Chicken: Cut the chicken up, separating every joint, and wash clean. Salt and pepper it, and roll into flour well. Have your fat very hot, and drop the pieces into it, and let cook brown. The chicken is done when the fork passes easily into it. http://digital.lib.msu.edu/projects/cookbooks/html/authors/author_fisher.html After the chicken is all cooked, leave a little of the hot fat in the skillet; then take a tablespoon full of dry flour and brown it in the fat stirring it around, then pour water in and stir till the gravy is as thin as soup.

See Fisher, Abby. What Mrs. Fisher Knows About Old Southern Cooking, Soups, Pickles, Etc. San Francisco: Women’s Cooperative Printing Office, 1881. Reprint, 1995, Applewood Books, Bedford, MA. Originally published in 1881.