In 1967, Louisville, Ky. was embroiled in the civil rights movement as Black citizens protested for many months to get the city to pass a law banning discrimination in housing and borrowing.

As the Kentucky Derby neared, many feared that protesters planned to disrupt the race. Tensions flared and negotiations between the city and movement leaders went nowhere. Eventually one of the protest organizers, A.D. King, sent word to his brother to come help the situation. His brother was a brilliant and widely respected organizer named Martin Luther King, Jr.

Days before Dr. King arrived in Louisville, a group of protesters held a sit-in on the stretch run at Churchill Downs in the middle of a race. They promised they’d be back on Derby day and in larger numbers.

The city was in a panic over the prospect of large-scale protests that would shut down their most-hallowed tradition. The National Guard sent troops. The Ku Klux Klan promised to show up at the Derby in full regalia.

Martin Luther King, Jr. arrived to a city brimming with tension and hostility. He feared that a protest at the Kentucky Derby would bring too much violence and do more harm than good. He convinced organizers to call it off, and instead held a rally downtown on the day of the Derby. Proud Clarion won the race at 30-to-1.

Black Lousivillians didn’t win their fair housing law until a year later when Democrats managed to take over the board of Aldermen with the help of Black voters and the AFL-CIO. This Louisville law later helped inspire the Kentucky Fair Housing Act.

Dr. Martin Luther King, Jr. (National Archives and Records Administration)

The next year Martin Luther King, Jr. was assassinated in Memphis, Tenn. while helping out with a similar local battle between striking sanitation workers and the city of Memphis. That week a horse named Dancer’s Image won the Governor’s Gold Cup at Bowie Race Course and the owner, Peter Fuller, donated all the winnings to King’s widow, Coretta Scott King.

That horse then headed to Louisville to contest the Kentucky Derby; a race he would win and later be disqualifed from because of traces of Phenylbutazone in his urine.

Fuller believed the disqualification was retribution for his support of Martin Luther King, Jr. and the civil rights movement. Fuller vowed to never return to Churchill Downs unless he had another horse he knew for sure could win the Derby. He said he’d name the horse Dancer’s Revenge.