For the first time since World War II, the Kentucky Derby will not take place on the first Saturday in May.

The Derby, the first jewel of horse racing’s Triple Crown, became the latest marquee sporting event forced to postpone because of the deepening coronavirus pandemic.

Tonya Abeln, a spokeswoman for Churchill Downs, said in an email on Monday night that the race would not go ahead as scheduled.

Churchill Downs will hold a conference call on Tuesday morning to announce a makeup date for the race, which is expected to be Sept. 5. The Courier-Journal newspaper in Louisville, Ky., where the race is held, had earlier reported the postponement and the new date.

The postponement came as Gov. Andy Beshear of Kentucky ordered schools and restaurants closed to try to prevent the spread of the virus in the state, where it has killed at least one person. Mr. Beshear, like many of his counterparts, urged the public to cancel gatherings.

The Derby, which promotes itself as the “most exciting two minutes in sports,” regularly draws more than 150,000 spectators to the famed racetrack with its twin spires. Many of them sip on mint juleps and it is customary for women to wear ornate hats to the race.

Kentucky officials also announced on Monday that they were postponing the state’s presidential primary from May 19 to June 23 because of the health emergency.

Keeneland, a racecourse in Lexington, Ky., that is home to the Blue Grass Stakes, said that it was canceling the spring race meet as well.