Unknown. 1944. “The "Summer House" - One of the beauty spots near the old U.S. Department of Agriculture adminstrative building in Washington D.C. circa 1900. It was reported to be a popular rendezvous for the famous old game of "Popping-the-Question.".” Special Collections, USDA National Agricultural Library. Accessed September 26, 2022, https://www.nal.usda.gov/exhibits/speccoll/items/show/7544.