Houston's strategy on public education was to attack segregation by demonstrating the inequality resulting from the "separate but equal" doctrine dating from the Supreme Court's "Plessy v. Ferguson" (1897). He orchestrated a campaign to force southern districts to build facilities for blacks equal to those for whites, or to integrate their facilities. He focused on law schools because, at the time, mostly males attended them. He believed this would obviate the fears whites expressed that integrated schools would lead to interracial dating and marriage. In "Missouri ex rel. Gaines v. Canada" (1939), Houston argued that it was unconstitutional for Missouri to exclude blacks from the state's university law school when, under the "separate but equal" provision, no comparable facility for blacks existed within the state.