In 1933, Lawson founded the New Negro Alliance (NNA) in Washington, D.C., along with John A. Davis Sr. and M. Franklin Thorne, to challenge white-owned businesses in black neighborhoods that would not hire black employees. The NNA instituted a "Don't Buy Where You Can't Work" campaign, considered radical at the time, and organized or threatened boycotts against white-owned businesses that did not hire blacks. In response, some businesses arranged for an injunction to stop the picketing. Lawson, the lead attorney, with assistance by Thurgood Marshall, fought back – all the way to the United States Supreme Court in "New Negro Alliance v. Sanitary Grocery Co." (1938). The court ruled that the organization and residents had a right to boycott. This became a landmark case in the struggle by African Americans against discriminatory hiring practices. Don't Buy Where You Can't Work groups multiplied throughout the nation. The NNA estimated that by 1940, the group had secured 5,106 jobs for blacks because businesses could not afford to lose sales of black customers during the Great Depression.