Hattie Yvonne Jackson, age 6, disappeared on July 21, 1961, from Rock Creek Park in Washington, D.C. She was last seen playing in the park with her older brother and friends. After a police officer warned the children to stop swimming in the creek, an unknown white man, described as about 30–40 years old with dark brown hair and a tan, wearing a white shirt and gray trousers, offered to take the children to another spot to swim; the children declined and the officer left. Shortly afterward Hattie vanished.

Witnesses later reported seeing two men helping a young girl matching Hattie’s description into a dull blue or gray older-model Chrysler near the park. Hattie was last seen wearing a white long-sleeved blouse, brown and white checkered shorts, pink sandals, and a blue hair ribbon. Extensive searches and investigations have turned up no trace and the case remains unsolved.

Anyone who was in Rock Creek Park that day or who has information about the described car or the men is asked to come forward.