Longstanding racial tensions between whites and blacks exploded in five days of violence that started on July 27, 1919. On that hot summer day, on a segregated Chicago beach, a group of white men stoned Eugene Williams to death when he crossed the unofficial barrier between the white and black sections of the 29th Street beach. Tensions escalated when a white police officer not only failed to arrest the white man responsible for Williams' death, but arrested a black man instead. Objections by black observers were met with violence by whites. Attacks between white and black mobs erupted swiftly. Because of the rioting, 38 people died (23 African American and 15 white), and another 537 were injured, two-thirds of them African American; one African-American Patrolman John W. Simpson was the only policeman killed in the riot.
After repelling the Hungarian attack, the Romanian army prepared to cross the Tisza River. From 27–29 July, the Romanian Army tested the strength of the Hungarian defense with small attacks. A plan was made to cross the Tisza River near Fegyvernek, where it makes a turn.