William Patterson was born August 27, 1891. In 1911, he was the first black graduate of Tamalpais High School in Mill Valley, California, going on to the University of California.
At the university, he became acquainted with African-American periodicals such as The Crisis, The Masses and The Messenger. After graduating with a law degree in 1919, Patterson joined the NAACP, where he met his future wife, Louise Thompson. Patterson traveled to London, where he met labor activists and members of the Labour Party , furthering his educational development. He also contributed articles regarding African-American issues to British newspapers.
In 1923, Patterson opened a law office in Harlem, which became involved in campaigns to free several defendants accused of political wrongdoing, including the Italian anarchists Sacco and Vanzetti. Patterson also took an active role in the Scottsboro Boys case as part of the International Labor Defense team of lawyers.
Patterson went to the Soviet Union, enrolled in Far East University, and participated in the famous Sixth Comintern Congress in 1927. In 1930, he was a delegate to the World Conference against Anti-Semitism and Racism, held in Paris, France.
After returning to the United States, Patterson continued his law practice, along with holding leading positions in the Civil Rights Congress and working as executive secretary of International Labor Defense. In 1951, Patterson and several other officials presented a petition to the United Nations charging the United States with genocide, a detailed documentation of massacres, lynchings, murder, torture, and bombing.
Later in life, Patterson became involved with the defense for Angela Davis and the Black Panther Party, providing useful advice and comradeship. Upon his death in 1980, he was mourned by generations of activists and freedom fighters.