In 1970, Burnham worked with CPUSA lawyer John Abt to defend Angela Davis, her friend since childhood, and later wrote the foreword to Abt's memoir.[5]
In 1977, she became the first female African-American judge in Massachusetts, serving as an Associate Justice of the Boston Municipal Court until 1982.[1]
On June 11, 2021, President Joe Biden nominated Burnham to be a member of the Civil Rights Cold Case Records Review Board.[7] The Senate's Homeland Security committee held hearings on Burnham's nomination on January 13, 2022. The committee favorably reported her nomination on February 2, 2022. Burnham was officially confirmed by the entire Senate via voice vote on February 17, 2022.[8]
Burnham has authored and coauthored numerous articles;[9] and one book, By Hands Now Known: Jim Crow’s Legal Executioners,[10] which examines the history of racialized lethal violence during the Jim Crow era. By Hands Now Known received positive reviews in The New York Times[11] and won the Los Angeles Times Book Prize for History in 2022.[12] It has also won the 2023 Hillman Prize for Book Journalism, and The Hurston/Wright Legacy Award. By Hands Now Known was also a finalist for the 2022 Kirkus Prize for Nonfiction, and has been named a Best Book of the Year by The New Yorker, Oprah Daily, Kirkus Reviews, Chicago Public Library, and Publishers Weekly.[13]