Dorothea Lange (1895-1965) was one of the best of the American photographers who used their art to document, and ultimately to alleviate, the human suffering caused by the Great Depression of the 1930s. As she viewed it, photography was not an end in itself, but a means of exploring the world so as to improve it.

Born of second generation German immigrants on May 26, 1895, in Hoboken, New Jersey, Dorothea Lange was named Dorothea Margaretta Nutzhorn at birth. She dropped her middle name and assumed her mother's maiden name after her father abandoned the family, one of two traumatic incidents in her early life. The other was her contraction of polio at age seven which left her lame throughout her life.

She attended public schools in New York City and from 1914 through 1917 was enrolled in the New York Training School for Teachers. At about this time she decided to...