Thomas Eakins as a young boy, 1850.

Thomas Eakins as a young boy, 1850.

A young boy with a hoop, Germany, 1902-1905.

A young boy with a hoop, Germany, 1902-1905.

Future photographer Alfred Eisenstaedt as a toddler with hoop. Germany, 1901.

Future photographer Alfred Eisenstaedt as a toddler with hoop. Germany, 1901.

Young Isabel Harter riding a tricycle while her sister Nellie rolls a hoop. Photograph by Wallace G. Levison. Fort Greene, Brooklyn, New York, May 1886.

Young Isabel Harter riding a tricycle while her sister Nellie rolls a hoop. Photograph by Wallace G. Levison. Fort Greene, Brooklyn, New York, May 1886.