She was represented by William H. Hastie, the former governor of the U.S. Virgin Islands and later a judge on the U.S. Court of Appeals for the Third Circuit, and Thurgood Marshall, legal counsel of the NAACP.

In 1946 in a landmark decision, the Court ruled that the Virginia law was unconstitutional, as the Commerce clause protected interstate traffic.

[2] In her 60s Kirkaldy started college studies, attending St. John's University in New York City; she received her bachelor's degree when she was 68 years old.

[3] Irene Morgan had been dealing with a recent miscarriage and was visiting her mother in Gloucester County, Virginia, to physically and mentally recover from the ordeal.

Hoping to go back home so she could continue working on the production line for the B-26 Marauder, Morgan boarded a Greyhound to return to Baltimore.

Since Maryland did not enforce segregation for interstate travel, Virginia's Jim Crow law could possibly not apply to Morgan.

[6] Her case, Irene Morgan v. Commonwealth of Virginia, 328 U.S. 373 (1946), was argued by William H. Hastie, the former governor of the U.S. Virgin Islands and later a judge on the U.S. Court of Appeals for the Third Circuit.

[7] The U.S. Supreme Court ruled 6–1 in 1946 that Virginia's state law enforcing segregation on interstate buses was unconstitutional.

African Americans continued to be ejected or arrested when they tried to integrate such facilities, as Southern states refused to obey Morgan v.

White Southerners attacked the Freedom Riders, attracting renewed national media attention to the South's Jim Crow system.

Morgan's case inspired the 1947 Journey of Reconciliation, during which 16 activists from the Chicago-based Congress of Racial Equality rode on interstate buses through the Upper South to test the enforcement of the Supreme Court ruling.

In a flagrant violation of the Morgan decision, North Carolina police arrested the civil rights activist Bayard Rustin.

A jury convicted him and he was sentenced to 22 days on a chain gang for violating the state's segregation laws, although he had been riding on an interstate bus.

[10] The 1947 Journey of Reconciliation, ahead of its time in the use of tactics of nonviolent direct action, inspired the highly publicized Freedom Rides of 1961, also organized by CORE.