[1] His mother, Mary Galt Patterson, had been born a slave in the state of Virginia and was the daughter of the organizer of a volunteer regiment of black soldiers who fought with the Union Army during the American Civil War.
[1] Patterson's father was a Seventh-day Adventist missionary to Tahiti and he spent extensive time there, with the rest of the family moving between the California cities of Oakland and Mill Valley, where William attended public schools.
[1] He saved up enough money to enter the University of California, Berkeley but was expelled during the years of World War I for his refusal to participate in compulsory military training.
[3] He failed the California State Bar Examination, however, and decided to pursue emigration to Liberia and took a job as a cook on a mail ship to England as a means to that end.
[3] Patterson was able to put his college degree to use by finding employment as a clerk in a law office, helping to write briefs, and studying to take the New York State Bar Examination, which he passed in 1924.