Gaines, a high school valedictorian who graduated with honors from Lincoln University in Jefferson City, Missouri with a Bachelor's degree in history, applied in 1936 for admission to the Law School at the University of Missouri, Columbia. In April, the university denied his admission on grounds of race. Missouri's policy at the time was to pay the expenses of black students' education out of state.
Gaines and his lawyer, Charles H. Houston took their case to court. After the Boone County court and Missouri Supreme Court both ruled in favor of the university, the argument proceeded to the United States Supreme Court, where Gaines v. Canada was argued on November 9, 1938 and became the most important segregation case since Plessy v. Ferguson.
On December 12, 1938, the court, in a 6-2 decision, ordered the State of Missouri to either admit Gaines to the University of Missouri or provide another school of equal stature within the state borders.
However, Gaines never attended the university. On the night of March 19, 1939, Gaines left his fraternity house in Chicago, Illinois, telling others he was going out to buy stamps. He was never seen again.
In 2001, the University of Missouri-Columbia renamed its Black Culture Center in Gaines' honor. Additionally, a scholarship offered by the UMC Law School is named for Gaines.