June 20, 1924. Washington, D.C. "Warm weather Mah-Jongg at Wardman Park Hotel pool. Left to right: Jane Eynon, Betty Carey, Helen Plummer, Ruth Nebecker." National Photo Company Collection glass negative. View full size.

The Potomac bathing beach with a view of the Washington Monument circa 1922. National Photo Company Collection glass negative. View full size.

June 16, 1923. Washington, D.C. "Arlington bathing beach." View full size. National Photo Company Collection glass negative.

Washington, D.C., 1922. "Potomac bathing beach." View full size. National Photo Company Collection glass negative, Library of Congress.

August 21, 1922. "Citizens' Military Training Camp, Camp Meade" (Fort Meade, Md.). National Photo Co. View full size. Nowhere on the Internet will you find a picture of more guys simultaneously jumping off a tree than the 10 shown here.

Washington, D.C., vicinity circa 1915. "Along the Chesapeake & Ohio Canal." National Photo Company Collection glass negative. View full size.

July 26, 1919. Washington, D.C. Swimsuit "bathing beach parade" at the Tidal Basin. View full size. National Photo Company Collection glass negative.

July 26, 1919. Washington, D.C. "Bathing beach parade." View full size. National Photo Company. Vertical stripes -- so flattering to a girl's figure.

Washington, D.C. (vicinity) circa 1915. "Along the C&O Canal." Last one in's a rotten egg. National Photo Company Collection glass negative. View full size.

August 22, 1925. Clarence Ross of the New York Athletic Club, winner of the first three-mile National Long Distance Swimming Race, on the Potomac River at the Key Bridge. View full size. National Photo Company Collection.

June 17, 1922. Washington, D.C. "Iola Swinnerton and Anna Niebel, winners of the bathing costume contest at the Tidal Basin. Miss Swinnerton, the runner-up, resides at 3125 Mount Pleasant Street N.W.; Miss Niebel, who took first prize, lives at 1370 Harvard Street N.W." National Photo glass negative. View full size.

1921. "Bathing Beach." Taking the waters somewhere along the Potomac River at Washington, D.C. View full size. National Photo Company Collection.

"Lansburgh bathing girls" in 1922 near Washington, D.C. Girl on the right: Iola Swinnerton. View full size. 4x5 glass negative, National Photo Company.

July 19, 1923. Washington, D.C. "Sunshine Girls at beach." The London dance troupe originated by the British musical-theater impresario John Tiller. View full size.

June 25, 1921. Washington, D.C. "Bathing Costume Contest." Note Felix/Krazy Kat doll. National Photo Company Collection. View full size.