Hank's father was a soldier in the U.S. Army in Texas and the Pacific (1929–1947) and after World War II, an educator and public school superintendent in upstate New York (1953–72).

O'Neal began taking photographs while a teenager, and he had his first exhibition in September 1973 at The Open Mind Gallery in New York City.

In the 1970s, he associated with a diverse group of photographers notably Walker Evans, André Kertész, and most importantly, Berenice Abbott, with whom he worked for the last 19 years of her life.

It documents efforts undertaken under the FDR Administration to create a visual, historical record of the situation in the United States during the Great Depression.

After Hank took the expressionless portraits of Warhol he decided to paint over the negatives after the shoot and in 2005 created digital versions of the images.