I found this photo: https://www.loc.gov/resource/anrc.01733/ at the Library of Congress and found this paragraph in the News Star on September 21, 1918 that I believe describes it:
Another way was when the people in town had a parade for the Liberty Loan, the girls took their service flag through the streets, being headed by a banner on which were the words: “We have done our bit ; you do your two bits.” They collected eighty dollars. The flag has over one hundred names on it.
Ouachita Parish History Tidbits 