Born and raised in Harlem, Walker learned photography at a young age by practicing with his uncle, Herbert Hoover Winfield. Encouraged by his mother, Florine Winfield Walker, he earned a B.F.A. from Empire State College and made photography his life pursuit. For more than 50 years, he photographed life in Harlem and surrounding areas. He taught at New York University and the International Center of Photography and lectured widely.

"A lifetime resident of Harlem, I have tried to document the world around me, particularly the African American community, especially in Harlem, from an honest perspective so that our history is not lost,” Walker said. “I am pleased that both my own photographic artwork and also some of the materials I have collected in my role as a cultural anthropologist will have a permanent home in an institution that will make them available to the public. I am so satisfied that this work has found a home in such a prestigious institution and can finally be shared with the world."

  Walker’s images depict scenes of daily life, city streets, parades and celebrations, poverty, drug use and policing, among other subjects. Walker made photographs of African American political leaders such as Jesse Jackson, David Dinkins and Elijah Muhammad, and cultural icons like Maya Angelou, Spike Lee, Toni Morrison, Dizzy Gillespie and Thelonious Monk.

Walker traveled outside of New York, photographing in cities throughout the United States, including Chicago, Los Angeles, Miami, Oakland and San Francisco. He photographed New Orleans following Hurricane Katrina in 2005. He also photographed abroad in places like Cuba, Guyana, Nigeria, Senegal and Mexico.